QP 36 
.B88 










Copy 1 




mm~^^mmmx^-™—m 










, ^hS\^^^^~^'"*^^'_ 






l»M 






I 



:. .. 







".\ ' " 



LIBRARY OF CONGRESS. 



@Sptp..-.:.„. §ojnjrtg)jt f o. 
Shelf .DLl.%. ■ 



UNITED STATES OF AMERICA. 



AY 24 1884 



Plate J. 




BONES. 



THE 



ECLECTIC 



PHYSIOLOGY 



FOR USE IN SCHOOLS 



BY 



ELI F. BROWN, M. D. 




VAN ANTWERP, BRAGG & 

CINCINNATI NEW YORK 






"£>■ 



Copyright, 1884, by 
Van Antwerp, Bragg & Co. 



PREFACE. 



The following treatise upon the human body has been 
prepared with special reference to its use in schools. Only 
such matter is given as seems needful to enable the pupils 
to fairly master the subject. Much useful supplementary 
material is added in the notes. 

The succession of topics adopted is such as long experi- 
ence has determined is the best. The simplest parts are 
studied first ; the most complex portions are considered last. 
The succession of topics is based on a plain order of depend- 
ence. Each subject is presented methodically. Simple 
topical outlines are annexed to the chapters to guide the 
pupils and teacher in systematic study and recitation. 

In presenting the various vital processes, and in the ex- 
amination of any great organ, attention is first given to the 
structure and use of parts. Hygiene then follows closely, 
because the discussions of structure and use determine the 
hygiene, and point to its immediate consideration. 

This subject is taught in the common schools in order to 

impart a clear knowledge of the nature and use of the body, 

and to impress forcibly the ways and means of maintaining 

(iii) 



iv PREFACE. 

its health and vigor. For these reasons, the subject matter 
is here presented in a plain, didactic style; common words 
are usually employed, instead of technical terms, and the 
details of anatomy are subordinated to the more important 
consideration of physiology and hygiene. 

Much attention is given to the care of proper sanitary 
conditions in the home, and to habits of healthfulness in 
ordinary life. Emphasis is given to the discussion of such 
habits as lead to pain and disease. The effects of narcotics 
and stimulants on the body and mind are set forth plainly 
and fully. The character of alcoholic beverages, tobacco, 
opium, etc., receives special attention. 

To teach physiology well, the teacher needs to prepare 
ingenious experimental illustrations, and to present to his 
class the examinations of appropriate materials from slaugh- 
tered animals. The teacher ought to know much more than 
these lessons contain. What is here given is designed for 
the pupils to learn. The teacher is advised to study care- 
fully the works of such authors as Gray, Flint, Huxley, 
Draper, Carpenter, and others of like character. In the 
preparation of this treatise, free use has been made of all 
the materials that constitute the great body of the science. 

Eli F. Brown. 
Irvington, Ind., \ 

May i, 1884. 1 



CONTENTS 



CHAPTER 








PAGE 


I. 


Introductory, . . . . . . . . . 7 


II. 


The Osseous System, 












12 


III. 


The Muscular System, 












. 26 


IV. 


The Skin, 












• 34 


V. 


The Teeth, 












• 43 


VI. 


Food, 












47 


VII. 


Digestion, 












54 


VIII. 


Circulation, 












65 


IX. 


Respiration, 












79 


X. 


Excretion, 












94 


XI. 


The Nervous System, 












98 


XII. 


The Nervous System, Concluded, . 








107 


XIII. 


Special Senses, — Touch, Taste, Smell, 








116 


XIV. 


Special Senses, Continued, — Sight, . 








123 


XV. 


Special Senses, Concluded, — Hearing, 








130 


XVI. 
XVII. 


Elementary Sanitary Science, . 
Emergency and Accident, 
Supplement, — Alcohol, . 
Glossary, ...... 








135 
145 
153 
171 




Index, - . 












183 



(v) 



PHYSIOLOGY 



CHAPTER I. 



INTRODUCTORY. 



Article i. Kinds of bodies. — The separate things we 
know about us are called bodies. By noticing these bodies 
we may see that there are two kinds: (i) bodies that do 
not live, (2) bodies that do live. The stones, the soil, the 
water, the air, pieces of iron, and such things, do not live 
and do not grow ; while the trees, the grass, the corn, the 
birds, the flies, the people, and such things, do live and 
grow. 

2. Contrast of non-living and living things. — Non- 
living bodies are formed and become larger by the addition 
of substance to the outside. Living things grow by taking 
food into themselves, which food they change so that, finally, 
it becomes a part of them. 1 * 

Non-living bodies are not inclined to change, but usually 
endure for a long time in the same condition. Living 
bodies originate from parent bodies, they live and grow for 



"These numerals throughout the book refer to the corresponding notes at 
the end of the chapter. 

(7) 



8 PHYSIOLOGY. 

a short time, and then die. No living thing can exist long 
as an individual. If we examine a non-living body we shall 
rind that all of its parts are much alike. For instance, the 
pieces of a stone are of the same kind, and are like the 
whole stone. The parts of a living thing are often very 
different. The roots of plants are not like the leaves. 
The bones of animals are not like the flesh. 

3. Organs. — The parts of a living thing are for different 
uses in the life and growth of the body. The roots of the 
plant absorb food from the soil. The leaves take food from 
the air, and change the food till it is prepared to become a 
part of the plant. The bones of animals support the body, 
the lean flesh moves the body, the eyes aid in seeing, the 
ears give hearing, and many other parts perform other uses. 

The different parts of a living body which perform the 
many kinds of work in the body are called organs. Thus 
the mouth is the organ for chewing, the heart is the organ 
for sending the blood through the body, the eye is the 
organ of sight, the lungs are the organs for breathing. 

4. Plants and Animals. — Living things are of two 
kinds: (1) plants, and (2) animals. Plants take their food 
from the air and water ; they have roots for the soil and 
leaves for the air and sunshine. Animals must have food 
that has been prepared for them by plants. Thus the horses 
and sheep feed on grass, the bees on the sweets of flowers, 
and men eat grains and fruits. 

A plant can not feel and is fixed to the soil by roots. 
Animals feel, they move freely, and show by their actions 
that they are intelligent. The lowest kinds of animals have 
very little feeling, and show scarcely any intelligence; they 
are much like plants. The higher animals are quick to 
move, acute in feeling, strong in action, and possess much 
intelligence. Man is the most highly developed animal. 2 

5. Human Body. — The human body is the only erect 
animal body. The average adult male Caucasian is five 



1XTR0DUCT0RY. 9 

feet eight and one half inches in height. The weight is one 
hundred and fifty pounds. The circumference of the chest 
is thirty-six inches. 

6. Systems of Organs. — The body is extremely com- 
plex in the systems of organs that operate in it. 3 

The chief systems of organs are as follows: (1) The bones, 
(2) the muscles, (3) the digestive apparatus, (4) the circu- 
latory system, (5) the respiratory organs, and (6) the nervous 
system. 

The bones support, the muscles move, the digestive appa- 
ratus changes the food, the circulatory system distributes the 
blood, the respiratory organs perform breathing, and the 
nervous system enables us to feel and to control the whole 
body. 

7. Parts. — The parts of the body are quite simple. They 
are as follows : (1) the head and neck, (2) the trunk, (3) 
extremities. The head consists of two parts, — the face and 
skull. The trunk consists of two parts, — the upper portion, 
called the chest, and the lower part, called the abdomen. 
The extremities are known as the upper and lower. 

8. Self-study. — In the study of the human body, we 
should bear in mind that we are learning about our own 
body. We need to examine it, and to find in it illustrations 
of what we learn. We can feel our own bones, muscles, 
joints, and skin. We can feel our own heart beat. We can 
observe our own breathing. Our own nerves tell us what 
feeling is. We know what hunger is. We know what health 
and sickness are. 

9. Why study Physiology? — We study the human 
body so that we may learn how to take care of it. Good 
health is one of the choicest blessings. It is hoped that the 
pupil will learn such lessons about the uses and care of his 
body that he may avoid disease, and make of his body a fit 
abiding place for the soul. 



PHYSIOLOGY. 



Notes. 



i. Structure of Stones.— The stones do not grow. They are 
formed. We may think of a tiny grain of stone, and, as matter of the 
same kind adheres to it on the outside, the grain becomes larger. Or 
the reverse may be true. A very large stone may wear away by the 
action of air, water, or other substance, and finally, by losing bits of 
itself, it becomes a tiny pebble or grains of sand. We can not tell 
how old the stones are. Many of the quartz pebbles that we step 
upon may have been formed in the early stages of the earth's devel- 
opment. 

2. Plants and Animals. — Many plants move upon being touched. 
Many of them move as freely as do some of the lowest animals. 
Some plants feed, in part, at least, on animal food. The "Venus 
Flytrap," and the "Sun Dew," are the most remarkable of the sensi- 
tive plants. Many of the lowest animals are like plants. They are 
fixed to a base, and do not move from place to place. Their parts 
resemble leaves and flowers. They have but little feeling, and show 
no intelligence. 

3. Cells.— Microscopic examination shows that every portion of 
the body is made up of minute sack-like forms, called cells. These 
cells are held together by various kinds of substance placed between 
the cells. The cells are the living, growing parts of the body. 

The cells are composed of an outer membrane and the contents 
of the membrane. The contents are usually fluid. The body grows 
by the increase in the number and size of the cells. 

The cells are formed into tissues. Thus, we have bony tissue, in 
which there is lime deposited among the cells, and cartilaginous 
tissue, in which there is elastic matter between the cells. 

The various tissues are as follows : 

1. Bony tissue, which is hard. 

2. Muscular tissue, which has the property of contraction. 

3. Connective tissue, which is tough. 

4. Cartilaginous tissue, which is elastic. 

5. Adipose tissue, which is fatty. 

6. Nervous tissue, which is sensitive. 

Suggestive Questions. 

What is a body? What are non-living bodies? What are living 
bodies ? What are organs ? What are some of the organs of a 



INTRODUCTORY. 



ii 



plant ? What are some of the organs of an animal ? How do plants 
differ from animals ? What are the dimensions of the average white 
man ? What systems of organs are there in the human body ? 
What are bones for ? What are muscles for ? What are the parts 
of the body ? What use may the pupil make of his own body in 
the study of physiology ? Why should we study physiology ? Of 
what value is good health ? 

Topical Outline. 



Bodies. 
Definition. 
Kinds. 

Non-living, 

Formed by addition to out- 
side. 

Not disposed to change. 

All parts alike. 

Have no organs. 
Living. 

Grow by taking food inside. 

Originate from parent bod- 
ies. 

Have a season of life. 

Die. 

The parts are unlike. 

Have organs. 
Kinds of Living Bodies. 
Plants. 

Food, from air and water. 

Have roots and leaves. 

Fixed by roots. 

No feeling. 

No intelligence. 
Animals. 

Food taken from plants. 

Have no roots or leaves. 

Move. 

Feel. 

Intelligent. 



The Human Body. 
Position. 
Height. 
Weight. 
Circumference. 
Systems of Organs. 
Bones. 
Muscles. 
Digestive. 
Circulatory. 
Respiratory. 
Nervous. 
Parts. 
Head. 
Skull. 
Face. 
Trunk. 
Chest. 
Abdomen. 
Extremities. 
Upper. 
Right. 
Left. 
Lower. 
Right. 
Left. 
Self study. 

Purposes of the study of 
Physiology. 



CHAPTER II. 

THE OSSEOUS SYSTEM. 

io. By pressing on the arm, we find the outer parts are 
soft and the deeper portions are hard. These hard portions 
are the bones. They form the frame-work known as the 
skeleton. 1 

ii. Uses of the Skeleton.— The skeleton gives: (i) 
general shape and permanency of form to the body; (2) by 
the aid of the fleshy portions that are attached to the 
bones, the skeleton supports the body in any desired posi- 
tion ; (3) the skeleton, by the aid of these soft parts, 
enables us to move and extend the limbs, as in walking and 
in reaching out the arms; (4) the skeleton protects many 
of the more delicate organs by furnishing bony cavities for 
their safe lodgment. For instance, the unyielding skull 
shields the brain, the cage formed by the ribs incloses the 
lungs and heart, and deep sockets protect the eyes. 

12. The number of bones that unite to form the 
skeleton is somewhat variable : anatomists usually recognize 
206, besides the teeth.' 2 The bones are divided into four 
great groups: (1) the bones of the head; (2) the bones of 
the trunk; (3) the bones of the upper extremities; (4) the 
bones of the lower extremities. 
(12) 



THE OSSEOUS SYSTEM. 



13 




13. The bones of the head are divided into the 
bones of the skull and the bones of the face. The bones 
of the skull are eight in number. They are broad and 
curved, so that when joined at their edges they form the 
walls of an oval cavity. This cavity contains the brain. 
Their edges interlock in strong, irregular seams, called sut- 
ures, which hold the bones 
firmly together. A thin pack- 
ing of cartilage is placed in 
the sutures. This cartilage 
has two uses: (1) it permits 
very slight motion in the sut- 
ure ; (2) it renders the shock 
from blows less severe to the 
brain, and the skull less liable 
to fracture/'' 

There are fourteen bones 
of the face. They are firmly 
fastened upon the front and 
lower portions of the skull. They are rigidly united with 
one another, excepting the lower jaw, which is free to 
move in opening and closing the mouth. These bones are 
extremely irregular in shape. They form the sockets of the 
eyes, the bridge of the nose, the prominence of the cheeks, 
the roof of the mouth, and the jaws. 

There is a U-shaped bone at the base of the tongue, 
called the hyoid bone, that aids in moving the throat in 
swallowing and in speaking. 

14. The bones of the trunk are divided into-. (1) the 
bones of the spinal column ; (2) the bones of the chest ; 
(3) the bones of the pelvis. The spinal column, or "back 
bone," extends from the head along the back, and supports 
the upper part of the body on the pelvis. This column is 
formed of twenty-four pieces, called vertebrae. These 
vertebrae are placed one upon another, with layers of car- 



Fig. 1. 

The Skull.— 1. Suturas. 



14 



PHYSIOLOGY. 



m 




Fig. 2. 

The Spinal Column. 



tilage between. 
This cartilage al- 
lows each verte- 
bra to move a 
little. 4 The com- 
bined motion of 
the vertebrae en- 
ables the spinal 
column to bend 
readily in any di- 
rection. The col- 
umn is exceed- 
ingly strong. An 
opening ex- 
tends lengthwise 
through the cen- 
ter of this col- 
umn, for holding 
the spinal cord. 

Each vertebra is broad in front. This 
broad part sustains the pressure of the 
column. On the sides and back portion, 
there are many irregular processes, by 
which the vertebra attaches to the various 
parts that surround it. 5 

15. The bones of the chest form 
a conical, bony cage. The bones that 
form the chest are a portion of the spinal 
column behind, the sternum or "breast 
bone ". in front, and the ribs at the side. 
The sternum is a flat bone, to which the 
cartilages of the ribs join in front. In a 
young person, the sternum is composed 
of three parts, but in later life these parts 
join firmly into one bone. 



Vkri kbra 
Processes. 



Fig. 4. 

Top View.— 1. Body. 2. 
• Opening for Spinal Cord. 



THE OSSEOUS SYSTEM. 



*5 




16. The ribs are twenty-four in number, twelve on each 
side. They are long and 
curved to form the walls 
of the chest. They are 
all fastened firmly to the 
vertebrae behind. In front, 
the seven upper, called 
the true ribs, are joined 
by cartilages to the ster- 
num. The next three are 
united by cartilages to the 
true ribs. The lowest two 
have no front attachment. 
By this arrangement, the 
chest is more yielding in 
its lower portion than in 
the upper region. 

17. The pelvis is composed of large bones, that form 
a stout, basin-like frame. This frame bears the weight of 
the parts above, and sup- 
ports the trunk upon the 
lower extremities. 

18. The Bones of the 
Upper Extremities. — 
The clavicle, or "collar 
bone," is braced against 
the sternum in front, and 
the scapula, or " shoulder- 
blade," is placed on the 
back. These two bones unite to form the prominence of 
the shoulder and a shallow socket in which the head of 
the humerus is held. This makes the shoulder-joint. The 
humerus is the long bone of the arm. The ulna, the inner 
bone of the fore-arm, joins with the humerus to form the 
elbow. The radius is placed by the side of the ulna, in the 




The Pelvis.— 1. Hi 
Coccyx. 



Fig. 6. 

Bones. 2. Sacrum. 3. 



i6 



PHYSIOLOGY 



fore-arm. These two bones twist about 
each other in turning the hand over." 
At the wrist there are eight pebble- 
shaped carpal bones, so united as to give 
great freedom of motion to the hand. 
The five metacarpal bones form the palm 
of the hand, and the fourteen phalanges 
form the fingers and thumb. 

19. The bones of 
the lower extrem- 
ities join the sides 
of the pelvis by the 
insertion of the head 
of the femur, or 
"thigh bone," in a 
deep socket of the 
pelvis. This forms 
the hip joint. The 
femur joins at the 
knee with the tibia, 
or " shin bone," of 
the leg. The patella, 
or "knee-pan," fits into the hollow of 
the knee in front. The tibia and fibula 
are placed side by side in the leg. At 
the ankle, these two unite with the seven 
tarsal bones to form the ankle joint. 
The tarsal and five metatarsal bones 
form the arch of the instep, and the 
phalanges form the toes. 

20. The Composition of the 
Bones. — The bones are composed of 
two kinds of matter : (1) a jelly-like sub- 
stance, known as the animal matter, and (2) a hard sub- 
stance, known as the mineral part. The bones of very 




Upper Extremity.—]. Clav- 
icle. 2. Scapula. 3. Hu- 
merua. 4. Ulna. 5. Radius. 
6. Corpus. 7. Metacarpal. 
8. Phalanges. 




Fig. 8. 



Lower Extremity. — 1. 
Head of Femur. 2. Femur. 
3. Patella. \. Tibia. 5. 
Fibula. 6. Tarsus. 7. Meta- 
tarsus. 8. Phalanges. 



THE OSSEOUS SYSTEM. 



17 






young persons contain much animal mat- 
ter, and the bones of old persons consist 
largely of the mineral substance. It is 
by the combination of these two kinds 
of matter that the bones possess their 
great strength. The mineral part makes 
them hard, and the animal portion pre- 
serves their toughness and elasticity. 7 
By burning a bone, the animal part is 
driven off by the heat, and the mineral 
portion is left in the form of a white, 
brittle body, resembling chalk. By plac- 
ing a fresh bone in weak acid for a few 
hours, the mineral part will be dissolved, 
and the animal part will remain. The 
animal part thus left will have the shape 
and size of the original bone, but will be 
so soft that it may be tied in a knot. 

21. The Structure of the Bones. — 
The long bones are so formed that they 
are hollow cylinders. This shape gives 
them great strength without the use of 
much matter, and makes them sufficiently 
large without their being heavy. The 
outer part is a dense, hard shell, but 
toward the center the matter becomes 
more porous, and the middle is a hollow, 
filled with a fatty substance, called mar- 
row. The ends are large, to render the 
joints strong. The outer shell of the end 
is thin, and the whole inner portion of 
the end is composed of numerous tiny cavities, separated 
by thin, bony partitions. These cavities are filled with 
fluid. By this means, the ends, though large, are not so 

heavy as if they were solid bone. Between the ends, the 
Pgy-2. 



Fig. 9. 



Section of Femur.— 1. Ex- 
ternal view. 2. Cellular 
portion at end. 3. Hollow 
in middle. 4. Thick shell 
of middle. 



i8 



PHYSIOLOGY. 



shell of the bone is much thicker, so that these smaller 
parts may be strong also. 

The bones are covered with a tough membrane, called 
the periosteum. This membrane protects and nourishes 
them. This tough cover, together with the many promi- 
nences and roughnesses on the bones, gives attachment to 
the soft parts (muscles) that move the bones. 

22. Minute Structure of the Bones. — The bones are 
filled with myriads of tiny chambers, passages and cells. 
These openings permit nourishment to pass through the 
bones. See hemes 10 and n. 



ft¥'$W 







Fig. 10. 



Longitudinal Section of Bonk 
(microscopic).— 1. Cells. 2. Ca- 
nals. 3. Intercellular Substance. 




Fig. ii. 

Cro«. Section of Bone (micro- 
scopic).— 1. Cells. 2. Canals. 

:i. Intercellular Substance. 



23. Joints. — The union of two or more bones is a joint. 
A joint may be formed for the purpose of binding the 
bones together firmly, as in the case of the sutures of the 
skull, or a joint may be for the free movement of the parts, 
as with the joints of the fingers; such unions as the latter 
are called movable joints. Movable joints are classified 
into: (1) hinge joints, such as the elbows and knees; (2) 
ball and socket joints, as in the case of the shoulder and 
hip joints; (3) compound joints, like the wrists; and (4) 



T//E OSSEOUS SYSTEM. 



19 



pivot joints, such as the rotation of the radius about the 
ulna, in the fore-arm. 

In movable joints, the ends of the bones do not touch 
each other. The ends of the bones are covered with a 




Fig. 12. 



Hip Joint.— 1 and 2. Cap- 
sular Ligament. 




F'g- 13- 



Hip Joint, with Capsular Ligament cut away. — 
1. Margin of Socket. 2. Portion of Capsular 
Ligament. 3. Round Ligament. 



layer of cartilage, which prevents the jar and wear that 
would occur if the ends of the bones rubbed together. 
The cartilage on each bone is covered with an exceedingly 
smooth membrane, called the synovial membrane. This 
membrane lines the whole inner surface of the joint. This 
membrane secretes a fluid between the surfaces that rub 
together, so that the joint moves with the greatest possible 
ease and smoothness. 

The great strength of a joint is due to the enlarged ends 
of the bones, and to the ligaments that bind the bones 
together. 8 These ligaments are formed of dense, inelastic, 
fibrous tissue. They are fastened from bone to bone, over 
the joint, so as to inclose the two ends of bone in one 
band, or capsule. Besides this capsular ligament that sur- 
rounds the joint, other short ligaments, within the joint, 



20 PHYSIOLOGY. 

fasten the ends of bone together. So strong are the joints 
that the limbs, in breaking, will usually break elsewhere 
than at the joint. 

24. Injury to the Joints. — The joints are often injured 
by violent twist or pressure. If the joint is so violently 
bent as to tear or damage its ligaments, the injury is called 
a sprain. A sprain produces great pain, and often requires 
a long time for recovery. The ligaments are slow to mend. 
The joint is usually weak for a long time afterwards. 

When one end of a bone slips from its proper place in 
the joint, it is said to be dislocated, or "out of joint." 
Such an injury is most likely to occur to the round head of the 
humerus, in the shallow socket of the shoulder. To return 
the bone to its place, requires skillful stretching of the 
joint, and pressure upon the dislocated bone. Dislocation 
weakens a joint, so that the same misfortune is likely to re- 
occur with a joint once injured in this manner. 

25. Growth of Bones. — The young bones are soft, 
and are composed in some cases of cartilage and in others 
of fibrous tissue. These soft bones have the proper shape 
and size. They become hardened by the deposit of mineral 
matter within them, until they are rigid bones. During 
life, the bones, like all other parts, are constantly under- 
going change of structure. The old material is being re- 
moved, and new matter is taking its place. 

26. A broken bone is repaired in the same manner in 
which the bone grows. At first, a watery fluid is poured 
out about the broken ends ; this fluid thickens day by day, 
until it is jelly-like and fibrous in composition. This 
matter hardens by the deposit of mineral matter, so that by 
the end of about six weeks the broken parts are quite 
firmly reunited. The union is frail, however, for several 
months. Finally the place of fracture becomes firm, and is 
even more strong, in some cases, than are the other parts of 
the bone. In order that the repair of the broken bones 



THE OSSEOUS SYSTEM. 21 

may proceed properly, they need to be held in position by 
stiff bandages. It is necessary, too, that the broken limb 
be kept quiet." 

27. Hygiene of the Bones. — The healthfulness of the 
bones is affected by the food. 10 If children are fed on diet 
that is deficient in bone-making substances, the bones do 
not become rigid and firm. Exercise strengthens the 
bones, by causing more blood to flow to them, and by 
forming the necessary deposit of matter in them for their 
growth. Great care needs to be taken not to deform the 
bones in early life by pressure and improper position. 
Injury is especially liable to occur to the bones of the chest 
by tight dressing, and to the spinal column by sitting or 
standing in stooped position. Habits and shapes acquired 
in this way in early life are scarcely to be remedied when 
the person grows older. 

Broken bones and injured joints require patient care, and 
deserve the attention of a skillful physician. 



Notes. 

1. Skeletons of Animals. — There are two plans of skeleton 
among animals: (1) In the higher animals, the frame- work is inter- 
nal, with the muscles arranged about it, the whole covered with a 
soft, pliable skin, as illustrated in all vertebrates, such as mammals, 
birds, reptiles, and fishes. Their skeletons are much like the human 
skeleton. (2) The animals below the vertebrates have the skeleton, 
or hard frame-work of the body, on the outside. Such is the case 
with insects, crabs, lobsters, mollusks, etc. In these cases, the skele- 
ton is a hardened skin ; the muscles that move it are within. 

2. The teeth are not included in the bones of the skeleton because 
they do not form a part of the frame-work. They resemble bone in 
structure and composition. They resist decay so perfectly that they 
are usually the last portions of the body to decompose. They are 
properly appendages of the skin, as are the nails and hair. They are 
treated of more fully under the organs of digestion. 



22 



PHYSIOLOGY. 



3. The skull bones are formed of double plates, an outer and an 
inner, between which there is a packing of spongy bone. This 
arrangement gives them great strength in the resistance of fracture 
by blows. In many cases, the skull has been known to turn aside a 
pistol or rifle bullet rather than suffer it to enter the brain. In in- 
fancy, the sutures are large; in middle age, they are narrow, but dis- 
tinct; in old age, they nearly disappear by the growth of bone. 

4. The pads of cartilage between the vertebrae vary in thickness 
from one fourth to one half inch. These plates make the column 
elastic, so that the brain rests upon it without jar or shock. These 
layers diminish in thickness by pressure, so that the column may 
bend from side to side, or forward and backward. The pressure of 
the weight of the body during the day makes the plates thin, and 
the column as a whole shorter than it is after they have expanded 
during the night. For this reason a person is slightly taller in the 
early morning than at evening. 

5. The spinal column curves forward in the neck, backward in 
the dorsal region, forward in the lumbar portion, and backward in 
the pelvis. Frequently the curve in the dorsal region is greatly in- 
creased by sitting and standing in a stooped position. Such de- 
formity tends to injure the chest. The column in its proper form 
bends neither to the right nor to the left. Frequently curvature to 
one side occurs because of weakness or from ill position 111 sitting, 
standing, or lying. Such curvature, though small at first, is a very 
serious deformity, and needs the attention of a physician. It may 
be relieved by exercises that tend to straighten and strengthen the 
spinal column. The position in school, in sleeping, in sewing, in 
sitting, and in standing needs constant attention. 

6. The radius and ulna are placed side by side in the fore-arm, 
so that, when the hand lies with the palm upward, the radius is on the 
outer side. The ulna joins with the humerus at the elbow, forming a 
hinge joint, the head of the radius being fitted into a ring or collar on 
the side of the ulna ; at the wrist, the radius joins with the carpal 
bones, and the head of the ulna fits into a collar on the side of the 
radius. In turning the hand over, the ulna remains fixed, and the 
radius turns over it. By grasping the fore-arm with the hand, one 
may feel the motion of the bones as they twist about each other. 

7. Bones. — It is the animal part of the bones that is used in the 
making of soups and jellies. This portion is extracted by boiling. 
Glue is made from the animal portion taken from the feet of 
slaughtered animals. The mineral part of the bones is used in mak- 



THE OSSEOUS SYSTEM. 23 

ing manure. In some regions of the world, immense beds of fossil 
bones and other animal remains are productive of the most valuable 
articles for enriching the soil. Phosphorus, which was formerly 
much used for the preparation of matches, is obtained by the chemist 
from the bones of animals. 

8. The joints are held together in part by the fitting of the ends 
of the bones to one another, and by atmospheric pressure. Especi- 
ally is this true of the ball and socket joints. It is estimated that 
the head of the femur is held in the socket of the pelvis by the 
pressure of the air equal to eighteen pounds, a force sufficient to bear 
the weight of the whole lower extremity. The tendons that pass 
over the joints aid in holding the joints together. 

9. Broken Bones. — In cases in which bones are broken, place the 
sufferer in the most comfortable position possible, and the broken 
part as nearly as may be in the natural shape, keeping the parts from 
moving. Call a competent surgeon at once. If no physician can be 
obtained, place the broken bones in their natural position by gently 
but firmly stretching and pressing the parts. Bind the broken limb, 
not too tightly, with such a bandage as will prevent change 111 the 
position, and keep the parts quiet. The broken limb should be kept 
in a natural form at all times until the broken bones are firmly united. 

10. Rickets. — In cases in which children are ill-fed, they suffer 
from the disease called "rickets," in part, at least, because of the 
weakness and imperfection of the bones. In extreme cases of this 
kind, the bones are like wax. The lower extremities of very young 
children are frequently bowed outward at the knees before the bones 
are sufficiently strong to sustain the weight. Deformities of this 
kind should be carefully avoided. 



Suggestive Questions. 

Why are the bones hard? What makes them so? How is it they 
are almost as light as wood, but are much stronger ? How do the 
bones of young persons differ from the bones of old people ? Why 
are the broken bones of old persons difficult to repair? How do the 
sutures of the skull add to its strength ? Why is the skull ovoid ? 
What purposes are served by the cartilages between the vertebrae ? 
Why are the bones of the lower portion of the chest most yielding ? 
What elements in the structure of a joint give it strength ? Why do 
the joints move so easily ? 



24 



PHYSIOLOGY. 



What is the cause of " round shoulders?" What service does the 
clavicle perform ? If the clavicle is broken, how will the shoulder 
change in form ? What gives the wrists and ankles such freedom of 
motion ? Can you count the metacarpal bones of your hand ? Can 
you feel the movement of the radius and ulna in revolving the hand? 
How is each kind of matter obtained from the bones ? How are the 
bones affected by proper exercise ? How do the bones grow ? 



Topical Outline. 
Bones. 



i. General character. 

2. Number. 

3. Arrangement. 

4. Composition. 

a. Animal. 

b. Mineral. 

5. Structure. 

a. Gross. 

b. Minute. 

6. Joints. 

a. Design. 



b. Classes. 

c. Structure. 
Growth and Repair. 
Injury. 

a. Sprain. 

b. Dislocation. 

c. Fracture. 
Hygiene. 

a. Effects of exercise. 

b. Effects of food. 

c. Deformity. 



Bones of Skeleton. 
Head. 

a. Skull. 

( 1 ) Frontal— Front Fart of Skull I 

(2) Occipital— Back Part of Skull I 

(3) Parietal— Walls of Skull 2 

(4) Temporal — Temples 2 

(5) Ethmoid — Base of Skull 1 

(6) Sphenoid — Base of Skull 1 

(7) Ear Bones — Inside the Ear 6. 

b. Face. 

( 1 ) Nasal — Bridge of Nose 2 

(2) Lachrymal — Tear Tubes into Nose 2 

(3) Vomer — Partition in Nose I 

(4) Turbinated — Walls of Nose 2 



THE OSSEOUS SYSTEM. 



25 



(5) Malar — Cheek Bones 2 

(6) Superior Maxillary — Upper Jaw 2 

(7) Inferior Maxillary — Lower Jaw 1 

(8) Palate— Roof of Mouth 2 

(9) Hyoid — Base of Tongue 1 15 

2. Trunk. 

a. Spinal Column. 

(1) Cervical Vertebra; — Neck 7 

(2) Dorsal Vertebrae — Back of Chest 12 

(3) Lumbar Vertebrae — Back 5 24 

b. Chest. 

(1) True Ribs — Upper Part of Chest 14 

(2) False Ribs— Middle Part of Chest 6 

(3) Floating Ribs — Lower Part of Chest 4 

(4) Sternum — Breast-bone 1 25 

c. Pelvis. 

(1) Sacrum — Support of Column 1 

(2) Innominata — Hips 2 

(3) Coccyx— Below the Sacrum 1 4 

3. Upper Extremities. 

(1) Clavicle — Collar Bone 2 

(2) Scapula — Shoulder Blade 2 

(3) Humerus — Arm 2 

(4) Radius — Fore— arm 2 

(5) Ulna — Fore—arm 2 

(6) Carpal— Wrist 16 

(7) Metacarpal — Hand 10 

(8) Phalanges — Fingers 28 64 

4. Lower Extremities. 

(1) Femur — Thigh Bone 2 

(2) Patella— Knee Pan 2 

(3) Tibia — Shin Bone 2 

(4) Fibula — Brace of Tibia 2 

(5) Tarsal— Ankle 14 

(6) Metatarsal — Instep 10 

(7) Phalanges — Toes 28 60 

Total 206 

See Plate I. for the bones forming the skeleton. 



CHAPTER HI. 



THE MUSCULAR SYSTEM. 



28. The parts surrounding the bones are soft. These soft, 
« fleshy portions are the muscles. All the mo- 

tions of the body are produced by the action of 
1 the muscles. The bones and joints are nicely 
adapted for motion, but require the muscles 
to move them. The muscles are precisely 
like the lean meat of the ordinary slaughtered 
animal. They are of a deep red color. Their 
peculiar property is that of contraction and 
relaxation. By contraction they become 
shorter; by relaxation they are made longer. 
By contraction and relaxation, they move the 
bones and other parts to which they are 
fastened. The muscles give beauty of outline 
and roundness of form to the body. The 
skeleton, which is repulsive and deathlike, is 
imbedded out of sight in the muscles. 

29. The structure of the muscles may 
be best studied by taking a long muscle, such 
as the biceps in the front of the arm. 1 This 
Fig. 14. muscle is a long object, as shown in figure 14. 

bjceps muscle.-i. The middle portion is somewhat cylindrical 

iar u portion.' l in form, while the ends are tapering. The 

(26) 




THE MUSCULAR SYSTEM. 



-7 



middle portion is fleshy, and the ends are 
fibrous. The middle portion, which is the 
muscular part, is composed of layers and 
bundles of fibers that extend lengthwise of 
the muscle. Each bundle is encased in a 
sheath of extremely tough, elastic tissue. 
The fibrous coats of the bundles extend to 
the ends of the muscle, and compose the 
tendons that attach the muscles to the 
bones. Each bundle is in turn made up 
of many tiny fibers of muscle, each fiber 
being covered with its delicate coat of 
fibrous matter, as is represented in figures 
15 and 16. These minute fibers of muscle 
are composed of many little muscular cells. 
The cells are the part of the muscle that 
possesses the property of contracting and 
relaxing. By the influence of the nerves 
that lead to the muscles, each cell may be 
caused to shorten slightly. It is the short- 
ening of all the cells that causes the muscle 
to become shorter and broader. The short- 
ening of the muscle pulls the bone and 
causes motion. The whole muscle is en- 
closed in a dense layer of fibrous tissue, 
which also covers and forms a large part 
of the tendons. The tendons fasten to the 
bones by the union of the tendonous fibers 
with the periosteum and bone matter. 2 

30. The action of the biceps muscle may 
be felt by grasping the arm tightly while 
the fore-arm is extended. Now, as the 
muscle pulls the fore-arm up, the change 
in form may be felt as the muscle becomes 
short, full, and firm. In figure 17, we see 




Fig- 15- 

Minute Muscular Tis- 
sues. — 1. A bundle of 
fibers torn to show the 
separate fibers, greatly 
magnified. 2. Detached 
fibers. 




Fig. 16. 



A Single Fiber Part- 
ly Broken and Great- 
ly Magnified. — 1. The 
delicate fibrous cover 
unbroken. 2. The 
muscular substance 
within, separated. 



28 



PHYSIOLOGY. 



the muscle is long and relaxed, while the fore-arm is ex- 
tended. In figure 18, the muscle is contracted and the 

fore-arm is drawn upward. The 
muscle is attached to the bone 
of the fore-arm near the elbow, 
so that a slight change in the 
length of the muscle causes 
much movement of the fore-arm. 
31. The muscles that close the 
fingers are placed on the front of 
the fore-arm, and those that open 
the hand are on the back of the 
fore-arm. The long, slender ten- 
dons that reach from these mus- 
cles to the fingers, pass along the 
wrist and hand to the joints of 
the fingers. By grasping the fore- 
arm, the muscles may be felt in 
their motion, and, by pressure on 
the wrist, the tendons may be 
felt like so many strong cords. 
32. Arrangement and Class- 
es. — The muscles weigh more 
than all the rest of the body. 
There are more than double as many as there are bones. 
They are usually placed in pairs, on opposite sides of the 
parts they are to move. Muscles that bend the joints are 
called flexors; such as straighten the joints are extensors. 
The muscles are of various shapes. On the body and head 
they are broad and flat, while on the extremities they are 
usually long and tapering. In some cases they are circular 
and ring-shaped. The heart and stomach are hollow 
muscles. 

The muscles are either voluntary or involuntary. The 
voluntary muscles, such as those of the arm, are under the 




Fig. 17. 

Biceps MosCl k Rki a\ e a. — 1 
of the muscle. '.'. Muscula 
Tendon fasten i 11 '-' t<> the fore 



!. Two beads 
portion. 4. 



THE MUSCULAR SYSTEM. 



29 



influence of the will, and hence 'move as the person 
chooses. The involuntary muscles do not move by the 
choice of the person. The 
muscles of the heart are in- 
voluntary. 

33. Exercise and Rest. — 
Each muscle requires inter- 
vals of work and rest. Re- 
laxation is the resting, and 
contraction the working stage 
of the muscle, hence it is 
that each muscle alternately 
contracts and relaxes. Rest 
and sleep must intervene 
between seasons of work, to 
restore the wasted parts and 
to renew the energies. Dur- 
ing sleep, the whole muscu- 
lar system becomes relaxed. 
The will ceases to direct the 
voluntary muscles, and the 
involuntary system is reduced in energy, as is seen in the 
slower action of the chest and heart. During the waking 
hours, all is activity and wear, but, during the quiet season 
of sleep, the parts are built anew. The muscles of the 
chest, heart, and alimentary canal also gain rest during the 
day by performing their tasks in intervals of work, followed 
by corresponding rests. For instance, the drawing in of 
the breath, which is done by muscular action, is nearly 
equalled by the time of breathing out the air, which admits 
of muscular rest. The muscles may be relieved by change 
in employment, which calls into action other parts of the 
body. Such changes are often quite as beneficial as quiet 
rest. It has been recommended that the day be divided 
into three equal parts, — eight hours for vigorous work, eight 




Biceps Muscle Contracted to Raise the Fore- 
Arm. — 1, 3. Two heads fastened at the shoulder. 
2. Contracting portion. 4. End fastened to the 
fore-arm. 



3 o PHYSIOLOGY. 

for refreshment and recreation, eight for sleep. Probably 
no better division can be made. After a season of work, 
the muscles not only need rest, but require nourishment. 
Proper exercise increases the strength of the muscles by 
causing them to receive more blood and to take more 
nourishment. The strongest muscles are such as are most 
often used, provided they are properly rested. The weakest 
muscles are those that are used least. If the arm be bound 
for a season motionless to the body, its muscles become 
pale, soft, and weak, until, by continued disuse, the muscles 
become too feeble to raise the arm. 

To be productive of good results, exercise needs to be 
taken at regular intervals, and at such times as do not inter- 
fere with digestion. Exercise should be taken in proper 
position, so that respiration and circulation may proceed 
rightly. It is best to exercise in the sunlight and pure air. 

Very skillful movements of the muscles are acquired by 
repeated exercise of them under the direction of the mind. 3 
The wonderful ease with which one walks, speaks, writes, 
and performs so many extremely complex movements, is 
due to constant effort and repetition. 

Notes. 

i. Composition of Muscular Tissue. — It is impossible to deter- 
mine the exact chemical composition of muscular tissue, since other 
structures, such as blood-vesseb, nerves, and connective tissue, are so 
intimately blended with it. Berzelius gives substantially the follow- 
ing estimate of constituents: 

Proper muscular substance, .... 15.8 per cent. 
Gelatin, Albumen, Hematin, .... 4.1 " 

Phosphate of Calcium and Albumen, . .1 " 

Alcoholic and watery extracts, . . . 2.8 " 

Water and loss, 77.2 " 

100. 



THE MUSCULAR SYSTEM. 31 

2. Uses of the Muscles. — The muscles, under the control of the 
nervous system, perform many of the most important processes in the 
body. The muscles of the chest are engaged in respiration; the heart 
circulates the blood ; the muscular walls of the stomach and intestines 
aid in reducing the food, and pass it through the alimentary canal ; 
the muscles of the face are engaged in the movement of the jaws and 
eyes, and in the expression of emotions, such as pain, grief, and joy; 
and the muscular movements of the larynx control the action of the 
vocal cords in making the sounds of the voice. 

3. The Hand. — The structure of the human hand, by which it 
admits of such diversity and complexity of movement, and by which 
it is so admirably adapted to perform the demands of the mind, is one 
of the best illustrations of the wonders of the human body. Attached 
at the ends of the long arms, they command a region of six feet in 
diameter, centered at the chest. The compound joints at the wrists 
give universality of motion ; so, too, the thumb, supplied by many 
muscles, designed for its special motion, opposes itself with ease to 
any one of the fingers, or forms with them the hollow of the hand, 
or grasps against them the hand of another, or lays hold of any de- 
sired object. By muscular practice, in close union with thought, the 
hand becomes the forcible and significant instrument of expression by 
gesture, the rapid writer of words, the marvellously skillful organ of 
delicate touch by the musician. It is estimated that, in the rapid 
playing of a skillful pianist, no less than 950 movements of the fingers 
are made in a minute. 



Suggestive Questions. 

What elements of beauty do the muscles supply ? What is their 
special purpose ? What is their essential property ? What causes 
the muscles to move ? How may one feel the action of the muscles ? 
What is the service of the fibrous tissues of the muscle ? Why is the 
lean meat of an ox tough ? How are the muscles attached to the 
bones ? Where are the muscles that move the fingers in closing the 
hand ? What advantage is there in their being so located ? 

Where are the muscles that move the jaw in chewing? How is 
the body held erect ? How is a joint held so that it may be stiff? 
What rest does the heart have from labor ? How may exercise be 
taken so as to increase strength ? How may exercise weaken the 
muscles? How are the muscles attached to the bones so as to pro- 



3 2 



PHYSIOLOGY. 



duce much motion by slight contraction ? Why are the muscles not 
located on the bones they are to move? What kind of muscle closes 
the eye firmly ? Why does the thumb possess such diversity of 
movement? Why should a person have change of employment? 



Topical Outline. 



Muscles. 



Purpose. 

a. To produce motion. 
/>. To give roundness of form. 

Structure. 

a. Muscular portion. 

(i) Bundles and layers. 

(2) Fibers. 

(3) Cells. 

b. Tendonous portion. 

(1) Fibers. 

(2) Attachment. 
Essential property and action. 

a. Contraction of cells. 

b. Contraction of whole muscle. 
Number and arrangement. 



5. Classes. 

a. On basis of form. 
(i) Long. 

(2) Broad. 

(3) Circular. 

(4) Ring-shaped. 

b. On basis of direction of mo- 

tion. 

(1) Flexors. 

(2) Extensors. 

c. On basis of control. 

(1) Voluntary. 

(2) Involuntary. 

6. Hygiene. 

a. Effects of proper exercise. 

b. Necessity of rest. 



Names and Action of the Principal Muscles. 



Head : 

Occipito-Frontalis . . . .Elevates the eyebrows. 
Corrugator Supercilii. .Wrinkles the brow in frowning. 

Orbicularis Oculi Closes the eye-lids. 

Levator Palpebral Opens the eyes. 

Recti (four in number) Move the eyeballs. 

Temporal Raise the jaw in chewing. 

Masseter Raise the jaw in chewing. 

Orbicularis Oris Closes the lips firmly. 

Buccinator Moves the cheeks. 



PlateD. 




THE STROBRIDGE inn. CO CIUCIKHATI 



THE MUSCULAR SYSTEM. 

Neck : 

Sterno-Cleido-Mastoid. . .Draws the head forward. 

Digastricus Draws the jaw down. 

Scaleni Bend the neck from side to side. 

Constrictor Moves the pharynx in swallowing. 

Trunk .- 

Pectoral Draws the arm forward. 

Deltoid Raises the arm. 

Terres Major Lowers the arm. 

Serratus Magnus Elevates the ribs. 

Intercostal Elevate the ribs. 

Oblique Form the walls of the abdomen. 

Diaphragm Separates chest from abdomen, and 

larges chest in breathing. 

Erector Spinse Hold the spinal column erect. 

Upper Extremities : 

Biceps Flexes the fore-arm. 

Triceps Extends the fore-arm. 

Pronator Turns the fore-arm inward. 

Supinator Turns the fore-arm outward. 

Flexor Carpi Radialis. . .Bends the wrist forward. 

Flexor Carpi Ulnaris. . . .Bends the wrist toward the ulna. 

Extensor Carpi Radialis. .Extends the hand. 

Extensor Carpi Ulnaris. .Extends the hand. 

Flexor Digitorum Closes the fingers. 

Extensor Digitorum. . . . Extends the fingers. 
Lower Extremities : 

Glutaeus Moves the thigh backward. 

Iliacus Draws the thigh forward. 

Psoas Magnus Draws the thigh forward. 

Rectus Extends the leg. 

Vastus Extends the leg. 

Biceps Flexes the leg. 

Gracilis Flexes the leg. 

Extensor Digitorum Flexes the foot and extends the toes. 

Gastrochnemius Extends the foot. 

See Plate II. 



Pgy— 3- 



33 



CHAPTER IV. 



THE SKIN. 



34. The Uses of the Skin. — The skin forms a beauti- 
ful, pliable covering for the body. By the exceeding tough- 
ness of the skin, the tender parts beneath it are protected 
from injury. The nerves of the skin tell when an object 
touches us. The skin keeps the body from getting very 
warm or very cold. The skin aids in removing waste 
matter from the blood. Since the uses are so numerous 
and different, the structure of the skin is necessarily com- 
plex. 

35. The Structure of the Skin. — The skin is com- 
posed of two layers. The outer layer is called the cuticle. 
The inner layer is called the cutis. The cuticle is fitted 
closely upon the cutis. See Fig. 19. 

The cuticle is formed of tiny, flat cells, closely packed 
together in layers. These cells are dry and scaly on the 
outer surface of the cuticle, while at the base they are soft 
and growing. The outer cells are constantly wearing off 
by friction, and are being replaced by the new cells from 
below. 1 The outer portion of the cuticle is horn-like, and 
resists the action of many substances which would injure 
the tender cutis. 2 On the palms of the hands and soles of 
(34) 



THE SKIN. 



35 




Fig. 19. 

Vertical Section of the Skin. (Microscopic). — 1. Cutis. 
2. Cuticle in layers. 3. Papilla. 4. Nerves of the Papilla. 
5. Opening of "Perspiratory Gland. 6. Perspiratory Gland 
entire. 7. Vessels for secreting coloring matter. 8. Blood- 
vessels. 



the feet, where the skin is subject to much pressure, the 
cuticle grows hard 
and thick. 3 The cu- 5276 

tide has no blood- 
vessels, hence it does 
not bleed; it has no 
nerves, hence it is 
without feeling. At 
the base of the cu- 
ticle, there are grains 
of coloring matter, 
which give com- 
plexion to the skin. 

36. The hair and 
nails are modifica- 
tions of the cuticle, 
however much they 
may fail to resemble it at first sight. 

The nails are formed of layers of cells that grow from a 
fold in the cuticle at the root of the nail, and that grow 
under the nail. These cells 
move forward toward the end 
of the fingers, so that the whole 
nail is renewed in about four 
months. The nails shield the 
ends of the fingers, preserve 
their sensitiveness, give firmness 
of grasp, and aid in picking up 
small objects. 4 See Fig. 20. 

The hairs are formed of cells from the cuticle 
hair grows from the top of a tiny bulb at the base of a 
deep sac in the skin. This sac is formed by a depression 
of the cuticle far into the cutis. The hair is cylindrical. 
It has a hollow throughout its length. This hollow is filled 
with air in the outer portion of the hair, and with liquid at 




■w---^ ,45<gfr 



Fig. 20. 



Vertical Section through the Finger 
End.— 1. Nail. 2. Cuticle. 3. Cutis. 4. 
Groove in Cuticle at the root of the Nail. 
5. Bone. 



Each 



36 



PHYSIOLOGY. 



its base. The coloring matter of the cuticle gives color to 
. the hair. Each hair is nourished at 

/ its inner end by the blood-vessels 

of the cutis. The hair grows from 
below, constantly pushing itself out 
through the sac. The hair is de- 
signed as a protection to the parts 
which it covers. When properly 
cared for, the hair is an element of 
beauty to the person. 5 See Fig. 21. 
37. The cutis, or true skin, is 
exposed to view when the cuticle is 
removed. This part is thicker than 
the cuticle. The cutis is composed 
mainly of fibrous tissue, so inter- 
woven as to make a very dense, 
tough mass. Leather, as it is pre- 
pared from the skins of animals, 
shows how largely the skin is com- 
posed of tough fiber. Through this 
tough body of the cutis, there is dis- 
tributed a network of minute blood- 
vessels, and the surface is thickly set with nerves. These 
blood-vessels and nerves are so numerous, that the point of 
a needle can scarcely enter the cutis without drawing blood 
and causing pain. 

38. The Glands of the Skin. — Located in the outer 
portion of the cutis, there are many small glands. These 
glands secrete an oily substance into the cuticle, and upon 
its surface. These are the sebaceous glands. They are 
designed to supply the skin with such matter as will pre- 
serve the softness of the skin, and will form a glossy dress- 
ing for the hair. 

More deeply imbedded in the cutis, there are great num- 
bers of very small tubes that are coiled into knots or glands 




A Hair.— 1. External part. 2. Saf- 
in skin. 3. Surface of Cuticle. 4. 
Sebaceous membrane. 5. Bulb at 
base. 6. Nourishing vessel. 



THE SKIN. 



37 



near the base of the cutis. These are the perspiratory 
glands. They receive the water from the blood, and pour 
it out on the surface of the skin. This water is called 
sweat or perspiration. The perspiration consists almost 
wholly of water. It contains minute quantities of salt and 
other impurities from the blood. 

39. Regulation of Temperature. — The evaporation 
of the perspiration cools the skin. When the body be- 
comes too warm, the pores of the skin open wider, so that 
the blood flows freely to the surface. Then the perspira- 
tory glands receive more than the usual quantity of water 
from the blood. They pour this water out on the surface 
of the warm skin. This water or perspiration evaporates, 
and cools the skin and the blood that flows through it. In 
this way, the warmth of the entire body is kept from rising 
too high. One may readily observe how evaporation cools 
the skin, by wetting one hand in warm water, and moving 
it rapidly through the air until dry. The hand that was 
wet soon becomes cooler than the other. 

When the body is exposed to cold, the pores of the 
skin close, and prevent much perspiration, so that the 
surface of the skin may be dry; this helps to keep the 
body warm. 

40. Hygiene of the Skin. — The skin will absorb many 
substances that are placed upon it. These substances make 
their way through the walls of the blood-vessels, and by 
entering the blood are borne through the system. Water 
and some liquid foods will enter the blood in this way in 
extremely small quantities. It is frequently by this action 
of the skin that poisons enter the blood, that contagious 
diseases are received by touch, and that medicines applied 
to the skin affect the parts beneath. 

The proper action and condition of the skin are neces- 
sary for the preservation of the health of the entire body. 
This leads us to consider the most direct means by which 



38 PHYSIOLOGY. 

the skin is affected. Two of these are : (i) The condition 
of the clothing, and (2) the cleanliness of the skin itself. 6 

41. Clothing. — The clothing, especially that which is 
worn next to the skin, needs to be clean and to be changed 
frequently. The underwear needs to be changed for two 
reasons: (1) To allow it to dry; (2) to keep it from being 
filled with effete matter from the body. When the clothing 
becomes filled with this waste matter, it prevents the skin 
from taking this poisonous waste matter from the blood. 
The underwear worn during the day should be laid off at 
night, so that these garments may be freely aired. The 
bedding should be exposed to the light and air during the 
day. Clean under-clothing, by its friction against the 
cuticle, and by its tendency to absorb the moisture of the 
surface, aids greatly in causing a healthful action of the 
skin. 7 8 

42. Bathing. — The skin itself becomes unclean in the 
following ways: (1) By the excess of oily matter from the 
sebaceous glands; (2) by portions of the perspiration left 
on it; and (3) by the dust that adheres to it. These 
various substances should be removed by bathing. For 
persons in good health, a daily cool bath will prove both 
pleasant and beneficial, if the following be observed: (1) 
The bath should be accompanied by a thorough rubbing of 
the skin with a rough towel; (2) this should be followed 
by brisk exercise. For persons who are less robust, a bath 
once or twice a week, in a warm room, with tepid water, 
followed by thorough drying and rubbing, may be suffi- 
cient. Every one needs to take at least one warm bath 
every few days. Soap should be employed to remove the 
greasy matter that fills the pores and covers the surface. A 
harsh cloth or flesh brush should be used to detach the old 
scales of the cuticle. A person is in no danger of suffering 
from cold or chill who takes his bath in a room heated to 
summer temperature, using water that is pleasantly warm, 



THE SKIN. 



39 



if he will thoroughly dry and chafe the skin until it be- 
comes reddened, and glows with warmth. Brisk exercise 
may follow, as a means of causing continued flow of blood 
to the surface and extremities. By giving proper attention 
to the bath, and by wearing clean, warm, dry clothing, the 
skin may be kept in healthy condition. 9 

43. Burning. — The most common, as also one of the 
most painful injuries to the skin, is caused by burning or 
scalding. If the burn is deep, it will cause both the cuticle 
and cutis to be removed, and make a wound that will re- 
quire a long time for recovery. Such an injury needs to 
have the air excluded from the part by some simple dress- 
ing, and to be kept clean and quiet, so that the skin may 
renew itself. Usually, in a burn, the cuticle only is raised 
in blister, which produces acute pain for hours after the 
occurrence. To relieve the burning pain, it is necessary to 
exclude the air from the burn. By submerging the burned 
part in cold water, or by wrapping the part in a bandage 
that is kept wet, or by coating the part with water and 
flour, the pain is readily relieved. A new cuticle soon be- 
gins to form next to the cutis, so that after a day's time or 
more the surface is covered and the injury is cured. 

Notes. 

1. The Cuticle rapidly Renewed. — The rapidity with which the 
cuticle is removed is shown by the short time that stains remain upon 
the skin. The whole cuticle is renewed within a few days. 

2. Protecting Power of the Cuticle. — The protecting power of 
the cuticle is illustrated by placing the hand in brine, weak lye, or 
acid. The cuticle resists the action of these substances, but, if there 
is the least crack or scratch in the cuticle, the cutis is caused to 
burn and smart by the contact of these fluids. Poison of almost any 
ordinary kind may be handled with comparative safety if the cuticle 
is entire, whereas poison is readily absorbed if the cutis is exposed. 
Doubtless, the cuticle often protects the body from becoming 
poisoned. 



4 o PHYSIOLOGY. 

3. The Cuticle Thickened. — The cuticle frequently becomes 
greatly thickened by pressure and friction, so that it irritates the 
cutis beneath and causes pain. Corns are produced in this manner 
upon the feet by tight shoes. To remove the corn, soak it in hot 
water, and pare off the thick cuticle with a sharp blade. Avoid the 
pressure, and the corn will not return. 

4. The nails require much care in order to keep them in proper 
condition. By frequently using a stiff brush upon them at the time 
of washing the hands, the folds of the skin at the edges and roots of 
the nails may be readily cleaned, while a sharp knife may be used to 
pare away the out-growing ends, and to remove the matter from 
beneath them. 

5. The hair is abundantly supplied with a natural dressing of 
oily matter from the skin, so that artificial pomatums are altogether 
needless. Unless much care is exercised in keeping the scalp clean, 
it becomes offensive with the excess of oily matter and the dust that 
adheres to the skin and hair. 

6. Perfumes and Cosmetics. — Perfumes may for a time over- 
power the odors that arise from an unclean body, but they can not in 
any sense serve the purposes of warm water in cleaning the skin, and 
of clean clothing in gracing the body. Cosmetics give the skin of 
the face an unnatural hue by their poisonous effects upon its tissues. 
Liquid arsenic is at the same time the most effective cosmetic and the 
most horrid poison. Ugly sores and blotches are liable to result from 
the use of such substances. 

7. The clothing is designed to protect the body against the cold 
of winter, the heat of summer, and the dangers resulting from sudden 
changes in temperature. Loose and porous clothing is warm. 
Woolen fabrics are most valuable in this respect. Garments made of 
wool are poor conductors of heat, and, when worn next to the skin, 
do not allow the warmth of the body to escape through them. They 
are not easily moistened by the perspiration, and do not readily give it 
off by evaporation. Flannel worn next to the skin is, for the reasons 
just given, an excellent protection against sudden changes in tempera- 
ture. In a climate such as exists in the central part of the United 
States, it is best to wear a suit of flannel under-clothing at all seasons 
of the year, unless it be during the midsummer. In winter, these 
suits should be increased until they will of themselves keep the body 
warm. Especially do the extremities need abundant protection by 
woolen clothing, in regions in which the winters' are severe. For the 
milder seasons, cotton fabrics may replace the woolen. They more 



THE SKIN. 41 

readily absorb the moisture of the skin, and lose it by evaporation. 
The coolest clothing is linen, which is particularly adapted to relieve 
the skin of its moisture, and to repel the direct heat of the midday 
sun in the summer season. The rubber overdress is most valuable in 
preventing the clothing from becoming wet by rain or snow ; and the 
rubber overshoes are useful for keeping the feet dry in case of mud and 
sloppy walks. These rubber articles should be laid off upon coming 
in-doors, as they prevent the proper escape of the vapors of the body. 
8. Air and Sunlight. — The healthy action of the skin is decidedly 
affected by the wholesome influence of fresh air and sunlight. Exer- 
cise in the open air, and in the strong light of the sun, gives such 
strength and vigor as will make the pale and puny indoor-dweller 
robust and rugged. Outdoor sports, brisk walks, rides, and all kinds 
of work under the open sky will invigorate every tissue of the body, 
purify the blood, quicken digestion, and enliven the whole body and 
spirit. The rooms in which persons sleep, and those in which they 
spend much time during the day, need the direct rays of the sun. 
Sunlight is the vivifying force of the entire organic world. 

9. Colds. — One of the most common afflictions is that of " taking 
cold." What is known as a "cold" is usually a congestion and in- 
flammation of the throat and lungs, or of some other internal mem- 
brane. Usually this condition is caused by wearing damp clothes, 
by getting the feet wet, by the sudden cooling of the skin after exer- 
cise, by sitting or lying on the damp ground, by undue exposure of 
the extremities, by exposing some part of the body to a current of 
cold air, or by chill in some other way. In all these cases, the cause 
is one that affects the skin so that the blood current through it is 
chilled, and the blood is sent in undue quantities to the delicate sur- 
faces within. Much may be done to relieve a "cold" by applying 
warmth to the extremities, and by such treatment as will relax the 
skin and excite it to an active condition of excretion and circulation. 



Suggestive Questions. 

How does the skin protect the body ? Why does it not break and 
crack by bending? Why is it so complex in structure? How does 
the cuticle protect the cutis? What are the uses of the hair and 
nails ? How do they grow ? How are the feathers of a bird like 
hair? What is leather? Might it be made from human skin? 
What is the use of the sebaceous glands ? How is the skin warmed ? 



4 2 



PHYSIOLOGY. 



Why does the skin become red with exercise ? How is the skin 
cooled ? How does wet clothing tend to produce chill ? What is 
the principal matter that the skin takes from the blood ? Why is 
poison sometimes received by touch ? What part of the clothing 
needs special attention as to cleanliness ? Why should a person not 
sleep in the underclothing worn during the day? Why does every 
person need to bathe ? How may a person prevent chill from 
bathing? How relieve the pain of a burn? What are the purposes 
of the skin ? 



Topical Outline. 



1. General Description. 

2. Structure. 

a. Cuticle. 

(i) Appendages. 
(a) Nails. 
(6) Hairs. 

b. Cutis. 

(i) Fibrous tissue. 

(2) Blood-vessels. 

(3) Glands. 

(a) Sebaceous. 
(/>) Perspiratory. 



(4) Nerves. 
. Purposes. 

a. Protection. 

b. Regulation of temperature, 
r. Removal of waste matter. 
d. Organ of touch. 

, Hygiene. 

a. Injury by absorption. 

b. Condition of clothing. 

c. Bathing. 

d. Treatment of burn. 



CHAPTER V. 



THE TEETH. 



44. Composition of the Teeth. — The teeth are ex- 
ceedingly hard bodies, set firmly in the bones of the jaws. 
They are designed to cut and grind the food. 

Each tooth presents three parts : 
(1) The crown, which is the portion 
seen above the gums ; (2) the roots, 
the portion imbedded in the jaw; 
(3) the neck, or middle portion sur- 
rounded by the gums. 

A vertical section (Fig. 22) shows 
that the main substance of the tooth 
is a hard, bone-like matter, known as 
dentine. Common ivory is dentine. 
The crown is covered with a layer 
of dense, hard substance, called 
enamel. The enamel is much like 
flint or glass, and is the hardest 
kind of matter in the body. The inner portion of the 
tooth is soft and pulp-like. In this internal portion are 
found the nerves and blood-vessels of the tooth. The 
nerves and vessels enter through small openings in the ends 

(43) 




Fig. 22. 

Vertical Section of a Tooth. — 1. 
Euamel. 2. Dentiue. 3. Pulp. 4. 
Blood-vessel. 5. Nerve. 6. Fibrous 
cement. 




44 PHYSIOLOGY. 

of the roots. The sockets in the jaw, and the roots that 
fit into them, are covered with a packing of fibrous matter 
that holds the teeth firmly in their places, and which serves 
as a cushion to prevent jar from biting hard food. The 
gums are composed of fibrous tissue, covered with a layer 
of mucous membrane. They aid in holding the teeth in 
place. 

45. Sets of Teeth. — There are two sets of teeth : (t) 
temporary, and (2) permanent. The 
temporary teeth are twenty in number, 
ten in each jaw. The front eight are 
flat and sharp, called incisors, or cut- 
ting teeth ; then four pointed, or cus- 
pid teeth ; and back of these, eight 
grinding, or molar teeth. This set be- 

Fig. 23. gins to appear when the child is but a 

Lower Maxillary Bone. few montns Q \^ an( J are a \\ present by 

the end of the third year. From the fifth to the eighth 
year they are gradually removed by a second set, that grow 
beneath them in the jaw, so that the teeth of the first set 
become loose, and are easily removed. 

The second, or permanent set, are larger and stronger 
iv . than the first, and are designed to 

fr'i;\j J J ; 1 ' ;, ;, , \ serve during the remainder of life. 
There are thirty-two in this set, six- 
teen in each jaw, as follows : eight 
incisors, with four cuspids, back 
of which are eight bicuspids (two 
Flg - 24> pointed), with twelve molars far back 

LNKNT Set, Sees 12* . 

*'*»"•• in the mouth. Figs. 23 and 24. 

46. Care of Teeth. — The teeth require careful atten- 
tion in order that they may be preserved in a sound condi- 
tion, free from decay and pain, and that they may, by their 
beautiful, pearly appearance, add so much to the beauty of 
the face in time of conversation. 




Full Permanent Set. 



THE TEETH. 



45 



To clean the teeth, it is well to brush them freely once 
or twice each day with a soft brush and water. To more 
effectually remove any deposit that may be upon them, oc- 
casionally employ powdered charcoal or finely pulverized 
chalk upon the brush. Even with this care, the saliva of 
the mouth will in many cases deposit a yellow crust of 
tartar about the edges of the gums, which needs to be re- 
moved frequently, else it will injure the enamel, and cause 
the teeth to appear unsightly. A quill or wooden tooth- 
pick should be used after a meal to remove any matter left 
between the teeth. It injures the teeth to pick them with 
pins. 

The enamel of the teeth, while it is extremely hard, and 
resists the action of almost any substance, is quite easily 
cracked or broken. Once injured, it is never restored, 
hence the great care that needs to be exercised. It may 
be injured by any of the following simple means : by sud- 
den changes in temperature, by very hot or cold food, by 
breathing very cold air through the mouth, and by cracking 
nuts between the teeth. 

When the enamel is removed, decay of the dentine sets 
in, and the tooth soon presents a cavity. The decay, as it 
reaches the nerves within, causes pain, and if not stopped 
it will destroy the tooth. For this reason the teeth need to 
be closely watched, and as soon as a cavity is detected it 
should receive the attention of a skillful dentist, and be 
properly filled with gold or some other substance that will 
prevent farther decay. 

By attention to cleanliness and repair, the teeth may be 
preserved during the life of the person, and the individual 
escape great pain and discomfort; besides, too, the general 
health will also be greatly enhanced. While the teeth add 
so greatly to the beauty of facial expression, they serve 
also as important organs in the distinct and natural articu- 
lation of sounds. 



4 6 



PHYSIOLOGY. 



Suggestive Questions. 

How are teeth adapted to their purposes? How is the crown pre- 
pared to resist wear and the action of substances? How are the 
teeth held in position? What causes the temporary teeth to become 
loose? At what age are the temporary teeth all removed? What 
kinds of teeth are found in the permanent set that are not in the 
temporary? How are the teeth injured? How may they be kept 
clean? What necessities are there for keeping them clean? What 
substance is it difficult to remove from them? 

How should a cavity be treated? Why should a cavity be filled 
early? What is tooth-ache? What uses do the teeth serve beside 
that of chewing the food? How may their condition affect the 
general health ? 

Topical Outline. 
The Teeth. 



1. General Character. 

2. Purposes. 

3. Structure. 

a. Parts. 

(i) Crown. 

(2) Roots. 

(3) Neck. 

b. Composition, 
(i) Dentine. 

(2) Enamel. 

(3) Pulp. 



Sets. 

a. Temporary 

b. Permanent. 
Preservation. 

a. Necessity of cleaning. 

b. Method of cleaning. 

c. Causes of fracture. 

d. Treatment of cavity. 



CHAPTER VI. 



FOOD. 



47. All substances that nourish the body are food. 
Every one is familiar with hunger and thirst. These feel- 
ings are demands for food and drink. Food is required for 
the growth of the body, to maintain the warmth, and to 
repair the wastes caused by exercise. 1 

Food is obtained from minerals, plants, and animals. 
The most nourishing food is obtained from plants and 
animals. 

48. The mineral substances that in any way serve 
as food, are as follows: (1) Water, which is supplied in the 
usual forms of drink, and is also part of many kinds of 
foods, especially fruits; (2) Various salts, such as com- 
mon table salt, lime salts, iron salts, and other mineral sub- 
stances. These are required to build up the teeth, bones, 
and some other parts. The salts that are taken as food are 
dissolved in the water we drink, and are contained in many 
of the grains we eat. 

49. The organic substances that are used as food 
are divided as follows: (1) Albuminoids, (2) Fats, (3) 
Sugars. 2 

Albuminoid foods are much like the various tissues of the 

(47) 



4 8 PHYSIOLOGY. 

human body. They seem best suited for nourishing the 
body, while at the same time they serve in part to produce 
its warmth. The most important articles of this group of 
foods are albumen, fibrine, and caserne. White of egg con- 
tains large quantities of albumen. Lean meat and wheaten 
bread contain both albumen and fibrine. The curd of milk 
is caseine. Persons who take much muscular exercise re- 
quire food of this kind. 

Fats are foods that are like the fatty portions of the 
body. The chief use of the fats is to keep the body warm. 
They serve somewhat to nourish the tissues and to preserve 
their strength. This kind of food is supplied by fatty 
meats, butter, kernels of nuts, and many oily grains and 
seeds. This kind of food is needed in Arctic regions, and 
during the winter seasons, to keep the body warm. The 
Esquimo delights in eating animal fats ; to him oils and 
tallow are delicious articles. 

Sugars include sugar, starch, and gums, and compose a 
large portion of the ordinary foods. These substances are 
found abundantly in corn, rice, wheat, potatoes, and ripe 
fruits. They serve admirably both to nourish and to warm 
the body. Observation and experience indicate that foods 
of this kind are to a great extent the proper diet for the 
people who live in the temperate regions of the earth. :< 
Fatty foods serve best for a frigid climate, grains for the 
temperate, and ripe fruits for torrid latitudes. 

A plain diet of nutritious food is better than one of 
elaborate mixture. A few articles eaten together are usu- 
ally better than a meal made of a single substance, because 
one kind may not contain all the elements needed to nour- 
ish the whole body. 4 Bread made of wheaten flour, or of 
the meal of other grains, eaten with ripe fruits, forms a 
safe combination of substances. Lean meat of beef, eggs 
and milk, served with grains, tubers, and fruits, are nutri- 
tious and wholesome. 5 



FOOD. 



49 



50. Drink. — The proper drink is pure water. Water is 
required in the- system to preserve the moisture and soft- 
ness of the various tissues. Many parts of the body are 
largely composed of water; thus, the blood is mainly 
water, and the nerves and muscles are three fourths water; 
even the teeth are one tenth water. Men can survive only 
for a few days without water, but they can live for many 
weeks without solid food. 

If the water used for drinking purposes is not pure, it 
should be filtered or boiled. By filtering it through char- 
coal, the solid impurities and bad odors. may be removed. 
By boiling it, the germs of disease that it may contain will 
be killed. Many cases of typhoid fever, and other serious 
diseases, arise from drinking impure water. 

Milk is both drink and food. Milk from unhealthy ani- 
mals should never be used. 

Tea and coffee, as commonly added to water for diet- 
drinks, are needless and expensive, and when used in ex- 
cessive quantities they are injurious to the human system. 
Much headache and indigestion result from the effects of 
these substances. They do not aid in nourishing and 
warming the body. Their influence is that of excitement 
and stimulation. 6 

51. Alcoholic Drinks. — Cider, beer, wine, and whisky 
contain alcohol. 7 It is the alcohol they contain that gives 
to them their peculiar intoxicating properties. While cider 
and beer are composed mainly of water, and contain small 
quantities of nourishment in the form of sugar, the alcohol 
they, contain leads to their use as drinks. The alcohol in 
such beverages does not act either as a food or drink. It 
creates thirst. It does not satisfy hunger. Its action on 
the muscles and nerves produces excitement and inflamma- 
tion. It tends to disorganize the blood, so as to produce 
diseased conditions of the heart, liver, and brain. Some of 

the most serious consequences that can occur to either mind 
Pgy.-4. 



5 o PHYSIOLOGY. 

or body, to health or character, result from the use of 
drinks containing alcohol. Persons who use such beverages 
acquire a craving for alcohol that often leads to the almost 
complete loss of their self-control, so that they have little or 
no power to resist temptation to drink such beverages in 
excess. In all of their forms, alcoholic drinks are too dan- 
gerous to be used as beverages. Alcohol is a medicine, 
not a food or drink. Medical writers, without exception, 
class alcohol as a poison. 8 

52. Cooking is designed: (1) To render food more 
easily digested, (2) to develop its flavors and make it more 
inviting to the senses, and (3), especially with meats, to 
destroy any germs of disease that may be in the food. The 
more simple and plain the manner of cooking, the more 
fully are these ends attained. When foods are boiled to- 
gether in a promiscuous manner, or fried so that grease is 
thoroughly mixed with them, or seasoned with much salt 
and spices, they are rendered less easily digested. Roast- 
ing and baking usually prove to be the best methods of 
cooking. 

53. Hygiene. — Health, as determined by food, requires: 
(1) That the articles used shall be sound and fresh; (2) 
that the food shall be suited to the season of the year and 
manner of life of the individual ; and (3) that ease of di- 
gestion shall not be prevented by bad cooking. 

Health requires that particular attention shall be given to 
the purity of the water employed for drink. The following 
rules should be carefully observed : 

Avoid shallow wells, and such as are near vaults and 
sewers. 

Use no water that will produce a scum when boiled. 

Protect cisterns and wells from receiving surface water. 

Use no water having a disagreeable odor or taste. 

Water from springs or deep wells, and filtered rain-water, 
are the safest to use. y 



FOOD. 



51 



Notes. 



1. Quantity of Food Needed. — The kind and quantity of food 
needed daily vary with the age, sex, occupation, and health of the 
person. It is estimated that a healthy man requires daily about one 
and two thirds pounds of oxygen from the air, four pounds or less 
of water, and about two and one third pounds of solid food, making 
about eight pounds during twenty-four hours. 

2. Composition of Foods. — Animal foods furnish albuminoids 
and fats, in 100 parts, as follows: 

Eggs Albuminoid 14 Oil 11 

Beef " 8 "30 

Pork " 4-5 " 50 

Cheese " 29 "30 

Butter " 1 "88 

Milk " 4 " 4 

Vegetable foods produce the three classes of foods about as follows, 
in IOO parts : 

Oat Meal Albuminoid 16 Starch 63 Oil I. 



Corn Meal 
Wheaten Flour 

Rice 

Beans 

Potatoes 



65. 
74- 
76. 

52. 
15- 



3. Flesh food is usually quite easily digested, and yields a ready 
supply of energy to the consumer ; it does not, however, serve the 
purposes of great endurance as fully as the grain foods do. 

4. Mixed Diet. — The inhabitants of frigid zones live almost ex- 
clusively on fats ; some mountain tribes in central Asia live on flesh 
alone ; one third the population of the globe live chiefly on rice ; in- 
habitants of torrid zones live principally on fruits. In a varied 
climate, such as that of the central United States, and with a class 
of people who live such active lives, it is best that the diet should 
not be confined to one article. No one kind contains all the elements 
needed for nourishment. 

5. Plain Diet. — The tendency, usually, is to depart from a plain 
and simple diet, and to resort to various mixtures, made palatable by 
artificial flavors. Such mixtures are often less nourishing and less 
easily digested than the more simple foods. 



5 2 



PHYSIOLOGY. 



6. Tea. — Mild solutions of tea tend to produce pleasant exhilera- 
tion and a temporary feeling of rest. This action is due to the stimu- 
lating effects of the theine and tannic acid which it contains. Con- 
tinued use of strong solutions of tea causes headache, indigestion, 
enfeebled action of the heart, and derangement of the nervous 
system. 

Coffee produces effects similar to those of tea. Continued use of 
strong coffee produces sleeplessness, headache, and indigestion. Its 
stimulating effects are due to the caffeine and essential oils it con- 
tains. 

7. Alcoholic Beverages. — The following classification of alcoholic 
beverages shows the percentage of alcohol they contain : 



Fermented, 



Alcoholic 
Beverages, 



Distilled, 



f Cider 

Beer 

Ale 6 to 10 

Claret 7 to 9 

Champagne 5 to 13 

Madeira 16 to 25 

Port 16 to 25 

Rum 60 to 70 

Whisky 50 to 60 

Brandy 50 to 60 

Alcohol, ordinary.. 75 
Alcohol, absolute.. 95 



3 to 10 per cent. 
3 to 10 



8. Alcohol does not Nourish. — That alcohol does not serve to 
nourish the body is shown by the following contrasts: 



A true beverage slacks thirst, 
and furnishes water to the tissues. 

Food is nutritious substance ; it 
enters the blood in a new guise ; 
it satisfies hunger ; it furnishes 
material for rebuilding the tissues. 

Heat-producing articles finally 
increase the temperature of the 
body, and the amount of carbonic 
acid exhaled. 



Alcohol produces thirst, and 
takes water from the tissues. 

Alcohol is innutritious ; it enters 
the blood unchanged ; it does not 
relieve hunger ; it furnishes no 
material for rebuilding the tissues. 

Alcohol finally lowers the tem- 
perature of the body, and dimin- 
ishes the amount of carbonic 
acid exhaled. 



FOOD. 



53 



g. 'Water Purifiers. — Filters remove bad odors and harmful sub- 
stances from impure water, by bringing the water in contact with 
charcoal. The charcoal absorbs the impurities. Boiling drives off 
the gases and coagulates the organic impurities. If a scum rises on 
water when it is boiled, the water contains organic matter and ought 
not to be used without being boiled. Salts are taken from water by 
causing the water to pass off in the form of steam. Steam from salt 
water is fresh. Rain-water is evaporated from salty seas. 



Suggestive Questions. 

Why is food required? What foods seem best suited for man? 
What substances are derived from the mineral kingdom? How do 
organic foods differ in character? What common articles supply 
albuminoid foods? What supply fats? What supply sugars? What 
seems to be the purpose of fatty food? Why does the Arctic in- 
habitant relish fat? How do the grains seem to be adapted to tem- 
perate regions? 

What grains afford the best food? Why is it not well to live on 
one kind of food ? Why is it not best to use a great variety of foods? 
What common articles eaten together form a suitable diet? Why do 
we eat butter with bread ? What is the proper drink ? What is the 
effect of tea and coffee? What is the nature of cider, beer, and 
wine? Why should a person not use these drinks? Why do we 
cook food ? How is health determined by food ? What injunctions 
are given concerning water? 

Topical Outline. 

Food. 



I. Definition. 


(2) Fats. 


2» Purpose. 


(3) Sugars. 


3. Sources. 


5. Drink. 


4. Classes. 


a. Water. 


a. Mineral. 


b. Other beverages. 


0. Organic. 


(1) Tea. 


(1) Albuminoids. 


(2) Coffee. 


(a) Albumen. 


(3) Alcoholic drinks 


(b) Fibrine. 


6. Cooking. 


{c) Caseine. 


7. Hygiene. 



CHAPTER VII. 

DIGESTION. 

54. The process by which the food is prepared to become 
the nutrient part of the blood is called digestion. The parts 
of the body by which the food is thus prepared are called 
the digestive organs. 

55. The Alimentary Canal. — Digestion is performed 
in a long, worm-like tube, called the alimentary canal. The 
alimentary canal begins at the mouth. It extends through 
the entire length of the trunk of the body. This canal is 
formed of three coats or walls. The inner wall is like the 
lining of the mouth. This inner coat is soft and moist, and 
is called the mucous membrane. The middle coat is mus- 
cular. The outer coat is smooth and soft. 

Certain parts of the alimentary canal have received 
special names. The opening back of the mouth is the 
pharynx. The straight tube, about nine inches long, lead- 
ing downward from the pharynx is the esophagus. At the 
lower end of this tube is an enlargement of the canal, form- 
ing a pear-shaped sack. This sack is called the stomach. It 
will hold about three pints. Connected with the stomach is a 
winding tube an inch or more in diameter and about twenty- 
five feet in length. This tube is called the intestines. 

56. Mastication is performed in the mouth. The food 
is held between the teeth by the lips, cheeks, and tongue, 

(54) 




DIGESTION. 55 

and is turned over and over by them. The strong muscles 
upon the sides of the head cause the teeth to cut and grind 
the food to pieces. At the same time the food is thoroughly 
moistened by the saliva which flows into the mouth from the 
three pairs of salivary glands. These 
glands are located as follows: (i) the 
parotid glands, just below and in front 
of the ears, (2) the sub-lingual, under 
the tongue, and (3) the sub-maxillary, 
under the jaw. Each of these glands is 
composed of a mass of tiny sacks and 
tubes, as represented in Fig. 25. The 
presence of food in the mouth causes Fi 

these glands to take watery fluid, called saiivaryGiandwith its duct, 
saliva, from the blood and to pour it into 
the mouth. 1 The use of the saliva is to wet and soften the 
food so that it may be easily swallowed. The saliva also helps 
to dissolve the starchy part of the food and turns it to sugar. 2 
This is why wheat grains, when chewed a short time, taste 
sweet. When the food is ready to pass from the mouth, it is 
pressed far back on the tongue, and is passed from sight and 
control into the pharynx. It then passes into the esophagus. 
In the esophagus, the muscular fibres above the food con- 
tract, and those below it relax, so that the food is swallowed 
into the stomach. 3 

The importance of proper mastication is evident, because 
no other part of the alimentary canal is designed to cut and 
grind the food. The more thoroughly the food is chewed 
and mixed with saliva, the more readily it is digested. Then, 
too, thorough mastication develops the flavors of the food 
and makes the saliva flow more freely. By proper chewing, 
the whole mass becomes sufficiently moistened, so that it is 
unnecessary to drink much water or other fluid at the time 
of eating, to "wash the food down." Much liquid taken 
with the food dilutes the saliva and juices of the stomach, 



5 6 PHYSIOLOGY. 

so that digestion is thereby weakened. Food that is thor- 
oughly chewed is properly started in the process of digestion. 
57. Stomach Digestion. — The stomach is placed just 
below the diaphragm, in the upper part of the abdomen. It 
lies across the body, with the large end toward the left side. 
Fig. 26 represents the stomach and liver as they lie opposite 
each other across the body, the stomach occupying the left, 




Fig. 26. 

Stomach and Liver,— 1. Esophagus. 2. Cardiac entrance, 3. Large end of stomach, i. Central 
portion. 5. Small end of stomach. 6. Pylorus. 7. Portion of Pancreas. 8. Duodenum. 9. Gall 
duct. 10. Hepatic artery. 11. Left lobe of liver. 12. Gall bladder. 13. Right lobe of liver. 

and the liver, the right side. The liver is represented as 
turned upward, to show its under surface. The esophagus 
leads into the stomach from above, through an opening called 
the cardiac orifice. The small intestine begins at an opening 
at the small end of the stomach, called the pylorus (gate- 
keeper). These openings are guarded by bands of muscles, 
which keep the openings closed so as to hold the food in the 
stomach for the proper length of time. 

When food enters the stomach, this organ is excited, and 
arouses from a quiet condition to one of activity. The blood 
flows to it in increased amount, so that its inner coat turns 
from a pale color to a deep red. The lining membrane 
becomes filled with the blood that flows into its minute 
blood-vessels. In this inner coat there are multitudes of 



DIGESTION. 



57 




Fig. 27. 



Section of Stomach. — 1. Cardiac orifice. 2. Folds of mucous 

membrane. 3. Muscular wall. 4. Pylorus. 5. Gall-bladder. 6. 

Duodenum. 7. Folds of mucous membrane. 8. Entrance of bile 
and pancreatic juice. 



tiny glands, called gastric glands. When the blood flows 
freely to the stomach, these gastric glands readily secrete 
large quantities of gastric fluid upon the food, just as the 
salivary glands pour out saliva in the mouth. 4 The gastric 
juice consists of 
water, containing 
some mild acids, 
and a peculiar sub- 
stance called pep- 
sin. It is by the 
action of the pepsin 
in the warm acid flu- 
ids of the stomach 
that the albuminoid 
foods are digested. 
The foods are all 
more finely divided 
and dissolved by the 
warm liquids and by the constant motion of the stomach. 

As the albuminoids are prepared to enter the blood, they 
gradually pass directly through the mucous lining of the 
stomach into the blood-vessels. The gastric juices are in 
like manner re-absorbed into the blood. After being passed 
through the liver to the heart, the food finds its way to all 
parts of the body, so that hunger is soon gratified, and the 
strength of the body is increased. Such portions of the food 
as are not digested in the stomach pass, little by little, as 
a thin grayish mass, through the pylorus into the intestine. 
The stomach, after a season of active labor for two or three 
hours, is again empty, and takes its season of rest and 
repair. 5 Fig. 27 gives an internal view of the stomach. 

58. Intestinal Digestion. — The small intestine is a 
long, crooked tube, hung in folds in the central portion 
of the abdomen. 6 It leads into the large intestine, or colon, 
which forms the last five feet in length of the alimentary 



58 



PHYSIOLOGY. 



canal. In Fig. 28, we see the small intestine as it is folded 
into a great mass in the central part of the abdomen, with 




Fig. 28. 

The Intestines. — 1. Beginning of Duodenum. 2. Small intestine. 3. Large intestine. 4. Rectum. 



the large intestine placed around it. The coats of the in- 
testines are the same in kind, number, and arrangement as 
those of the other parts of the alimentary canal, only they are 
much thinner. These coats have numerous glands in them 
which secrete the intestinal juices. The inner coat is not 



DIGESTION. 



59 




Fig. 29. 



A Villus. — Ideal section, greatly enlarged, 
showing minute capillary circulation. 



only folded, as is that of the stomach, but it is densely set 
with minute villi, or hair-like rootlets. These villi dip into 
the food matter so as to afford 
every opportunity for the ab- 
sorption of the nutrient particles, 
as the food is passed along by 
the worm-like motion of the 
muscular coat. See Fig. 29. 

The first few inches of the 
small intestine, called the duo- 
denum, serves somewhat as a 
second stomach. It is here that 
two peculiar fluids are received 
by a duct, one branch of which 
brings in the bile from the liver, 7 
and the other the pancreatic 
juice from the pancreas. 8 These two fluids are different 
from the gastric juices, for they are alkaline (like lye) instead 
of acid, and they act specially upon the fats, starches, and 
sugars. By the action of these fluids, the food in the intes- 
tine becomes changed into a milky substance, called chyle, 
which readily enters the blood. The length of time required 
for the complete digestion of the food varies with the different 
kinds of matter, and with the conditions of the system; 
usually it is accomplished in from one to three hours. 9 

59. Intestinal absorption of food occurs in two ways : 
(1) As in the stomach, so here, the fluids return to the blood 
by passing directly through the inner coat of the intestine 
and the walls of the minute blood-vessels with which the 
mucous lining is densely filled. (2) Other portions are taken 
up by minute tubes, which have their beginning in the villi 
of the lining coat, and which draw the matter into them- 
selves by the action of valves along their inner walls. These 
tubes are called lacteals, because the chyle that they draw 
from the intestines is milk-like in appearance. See Fig. 31. 



6o 



PHYSIOLOGY. 



^ 



60. The lacteals conduct the chyle from the intestines 
into numerous glands near by, called the mesenteries, from 
which a fewer number of lacteals lead the chyle into one 
large tube in front of the spinal column, called the thoracic 

duct. This duct conveys the 
chyle upward through the thorax, 
and pours it into a large vein 
under the left collar-bone. Fig. 30. 
By these two methods of ab- 
sorption, the food enters the blood 
and begins the process of nourish- 
ment. Such portions of the food 
as are not digested in the ali- 
mentary canal, pass into the colon 
and are finally cast out of the 
system. 

61. Hygiene of Digestion. 
— The health and vigor of the 
system depend in the greatest 
degree upon the efficiency with 
which the body is nourished, 
hence the conditions that affect 
the process of digestion are very 
important. Among the more com- 
mon points deserving attention 
are those set forth in the follow- 
ing article. 

62. The manner of eating 
needs to be such (1) that the food 
shall be thoroughly chewed; (2) 

that the food shall not be taken with too much drink, since 
much water dilutes and weakens the digestive juices ; (3) that 
very cold or very hot articles shall be avoided, since they 
change the temperature of the stomach; (4) that the food 
shall be eaten deliberately. 




Fig. 30. 



Thoracic Duct and Lacteals 
Mouth of thoracic duct. 2. Lower end 
of duct. 3. Mesenteries. 4. Lacteals. 
5. Intestine. 



— 1. 



DIGESTION. 



61 



63. The amount of food needs to be sufficient to re- 
store the waste of the system, and to satisfy the appetite, 
if it be a natural craving for food. Bread and fruit are 
much more easily digested than such substances as cheese, 
because they are not so concentrated. The amount of food 
required, as well as its kind, is much affected by exercise in 
the fresh air and sunshine. The active plow-boy needs more 
than the quiet school-fellow, and the former may readily 
digest such kinds of food as will prove quite 
indigestible to the latter. The quantity of 
food needed during crisp, freezing weather 
is much greater than that required in the 
lazy days of spring and summer. 

64. The frequency of meals, and the 
times of day at which they are eaten, need 
to be such that, after the organs have had 
opportunity to perform their work, they may 
have an equally long season for rest and 
repair. Three meals a day are sufficient for 
any healthy person, and a less number may be 
better for some. "Eating between meals" 
robs the organs of rest. Regularity in eat- 
ing is one of the most important of require- 
ments. Very late meals, or very heavy meals 
in the latter part of the day, often disturb 
the digestive organs. Light food in the 
evening will afford the best opportunity for 
sound and refreshing sleep during the night. 

Dreaming and restlessness are most frequently caused by 
excess of food, or indigestible matter, in the alimentary 
canal. It is improper to pass immediately from hard work 
of muscle or brain to the table, for the system needs time 
to prepare for the change. It is equally wrong to engage 
in active labor of any kind just after eating, for the forces 
of the system are required for a time in beginning digestion. 




Fig. 31. 



End of Lacteal, 
showing wall and 
yalves, greatly en- 
larged. 



62 PHYSIOLOGY. 

When one is tired or warm, let him rest before beginning 
to partake of food, and then eat deliberately. 

The conditions of the mind affect both the appetite and 
digestion. Food eaten under peaceful and agreeable influ- 
ences will receive the attention and energy of the digestive 
apparatus, while excitement, anger, sorrow, or discord will 
render the forces of the stomach almost powerless. 

65. Foreign substances are frequently very inju- 
rious to the action of the digestive organs. The juice of 
tobacco, swallowed with the saliva arising from chewing or 
smoking the substance, inflames and weakens the nerves 
of the stomach. So does the alcohol contained in beer, 
wine, and whisky. Much alcohol arrests digestion. Strong 
condiments, such as salt, pepper, vinegar, mustard, etc., 
when taken in large quantities, irritate the delicate lining 
of the alimentary canal and impair digestion. 10 



Notes. 



1. Glands are organs designed to take fluids from the blood. 
They change these fluids into juices, which they pour out for 
special purposes. This action of the glands is called secretion. 
Thus the perspiratory glands secrete perspiration, the lachrymal 
glands secrete tears, and the salivary glands secrete saliva. 

2. Starch and sugar are of the same chemical composition. 
The digestion of starch consists in changing it into a form of sugar. 
This is done by the ptyaline of the saliva, and the acids and ferment- 
ing juices of the stomach and intestines. Starch will turn to sugar 
by being boiled with weak sulphuric acid. In all fermentation of 
starchy grains, the starch turns to sugar. 

3. Swallowing. — How the food is caused to pass along the 
esophagus is illustrated by a horse as he drinks. Although his 
head may be low, he readily swallows the water upward into his 
stomach by contracting the muscles of the esophagus behind each 
swallow, and causing this contraction to run along the tube. The 
swallows may be seen to follow one another in wave-like form. 



^^M^HHIMMMHHMH 



DIG EST TON. 63 

4. Osmosis. — Gases and liquids pass readily through moist mem- 
branes. If a bladder that is filled with brine be placed in a basin 
of fresh water, some of the brine will pass out through the walls 
of the bladder, and some fresh water will pass into the bladder. 
The watery part of the blood passes through the walls of the 
capillaries and glands. This passage of liquids through membranes 
is called osmosis. 

5. Digestion Observed. — Through permanent openings accident- 
ally made into the stomachs of human beings, and openings purposely 
made into the stomachs of domestic animals, the process of di- 
gestion has been fully observed, and many experiments have been 
performed to test the digestibility of various kinds of food. 

6. Objects for Examination. — The viscera of the human body 
resembles very closely the corresponding parts of the common hog. 
The teacher and student may derive great profit from making close 
examination of the hog's intestines, stomach, heart, lungs, pancreas, 
liver, kidneys, and nervous matter. 

7. The liver is a large, dark-colored gland, weighing three or 
four pounds, located on the right side just below the diaphragm. 
Its action is intimately connected both with digestion and circu- 
lation. It secretes from the blood about three pounds daily of dark, 
greenish, bitter fluid, called bile. While the intestines are resting, the 
bile is stored in a sack on one side of the liver, called the gall-bladder, 
to be poured into the small intestine at time of digestion. The 
bile seems designed in part to act on the fatty foods, and in part 
to carry off certain impurities from the blood through the intestines. 

8. The pancreas is a long, flat gland, located just back of the 
stomach, weighing about one fourth of a pound. It is like the 
salivary glands in structure, and secretes a juice into the intestine 
to aid in the complete digestion of the foods. 

9. Digestibility of Food. — The following is the length of time 
required for digesting various articles of food : raw apples, two 
hours ; boiled beans, two hours and thirty minutes ; roasted beef, 
three hours; wheaten bread, three hours and thirty minutes; milk, 
two hours ; roasted pork, five hours ; boiled rice, one hour ; boiled 
potatoes, three hours and thirty minutes. 

10. Cleanliness of the Colon. — The matter which passes into 
the colon requires to be cast out of the body regularly. If de- 
tained, long in the colon, it irritates and inflames the organ, causes 
disagreeable gases, and produces painful constipation and indiges- 
tion. A regular daily habit is the only safe condition. 



6 4 



PHYSIOLOGY. 



Suggestive Questions. 

What definition of digestion may be given ? What is the meaning 
of the word digest? Why does food require digestion? In what 
different ways is the food changed ? What foods are chiefly digested 
in the stomach? What foods are acted upon by the intestines? 
What fluids are supplied in the different parts of the alimentary 
canal? What glands supply the different fluids? What importance 
attaches to proper mastication? How is food swallowed? 

What is the purpose of each coat of the stomach? What causes 
the food to pass along the canal? What is absorption? How does 
absorption occur in the stomach ? How does intestinal absorption 
take place? How does the matter which enters the lacteals reach 
the heart ? What relation does proper digestion bear to health and 
vigor? What points are important in the manner of eating? How 
does exercise affect the quantity needed ? How frequently should 
meals be eaten? At what times of day is it best to eat? How 
do strong articles like pepper and salt affect the alimentary canal? 



Topical Outline. 



Digestion. 



i. Definition. 

2. General Plan. 

3. Alimentary Canal. 

a. Mouth. 

b. Pharynx. 

c. Esophagus. 

d. Stomach. 

e. Small Intestines. 
/. Large Intestines. 

4. Changes Produced. 

a. Mechanical. 

b. Chemical. 

5. Divisions of Process. 
a. Mastication. 

(1) Organs engaged. 

(2) Changes produced. 

(3) Importance. 



b. Stomach Digestion. 

(1) Structure of stomach. 

(2) Changes produced. 

(3) Absorption. 

c. Intestinal Digestion. 

(1) Structure of intestines. 

(2) Changes produced. 

(3) Absorption. 
6. Hygiene. 

a. Manner of eating. 

b. Amount of food taken. 

c. Frequency of meals. 

d. Time at which meals are 

eaten. 

e. Conditions of mind while 

eating. 
f. Injurious foreign substances, 




Plate Iff. 



ORGANS OFCIRCULATION 



■ : S*P 5PI06E UTH CO.CIKCIf 



CHAPTER VIII. 



CIRCULATION. 



66. We now need to learn how the nourishment prepared 
by the alimentary canal is carried to every part of the 
body. This process is called circulation. 

In every living thing there is a fluid that is constantly 
moving through the entire body. In plants this circulating 
fluid is the sap. In all higher animals, including man, it 
is a warm, red liquid, called blood. 

67. The General Plan of Circulation. — The heart, 
like a tiny engine, forces the blood through long branching 
tubes that lead to every portion of the body. The blood 
then returns to the heart by running into other tubes, which 
empty into one another as do the streams of a river. These 
tubes finally empty the blood into the heart again in a con- 
tinuous stream. 

In the circulation through the body some very important 
changes occur in the blood: (1) In passing through the 
inner coats of the alimentary canal, it gains food; (2) in 
feeding the tissues, it loses its nutritious elements; (3) in 
passing over the worn-out particles in the body, the blood 
becomes impure by absorbing them ; (4) at other places, the 
blood is purified by having the waste matter removed. By 
Pgy.-5. (65) 



66 



PHYSIOLOGY. 



these changes, the blood fulfills its great purposes as follows : 
(i) It nourishes the parts; (2) it purifies them; and (3) it 
warms them. 

68. The blood is of a deep red color. It is somewhat 
thicker than water. It has a smooth quality, which causes 
it to flow very freely. It has a faint odor peculiar to the 
animal from which it is taken. It constitutes one twelfth 
the weight of the body. When the blood is examined by 
aid of the microscope, it is found to consist of two parts 1 : 

(1) Of vast numbers of mi- 
nute bodies of circular form, 
called corpuscles (little bod- 
ies) ; and (2) of the fluid 
part, called the plasma. The 
plasma is the greater portion 
of the blood. The plasma 
carries the corpuscles and the 
food particles, as the water 
of a muddy stream floats the 
multitudes of fishes and the 
tiny particles of solid matter 
that are in it. 

69. The corpuscles are 
far too small to be seen with- 
out the aid of a microscope. The greater number of the 
corpuscles have a redish-yellow hue, and give color to the 
blood. Some of them are colorless. They are disc-like in 
shape, as shown in Fig. 32. The corpuscles appear to be 
of use in carrying the gases of the blood to and from the 
lungs.' 2 

70. The plasma of the blood is a complex fluid. It is 
composed of two parts: (1) The greater portion is serum, 
which is chiefly water; and (2) it contains a small amount 
of fibrine in solution. This fibrine of the plasma is a 
peculiar substance, resembling the fibrine of lean meat and 




Fig. 32. 
Corpuscles.— 1. Colored. 2. Colorless 



CIRCULATION. 



67 



the gluten of flour, so that some writers speak of this fibrine 
as "lean meat in solution." 

71. The fibrine of the blood coagulates upon being 
exposed to the air; that is, it changes from its soluble or 
fluid form, to a stringy, tough mass, just as the albumen 
of egg hardens by being boiled. 3 By the coagulation of 
the fibrine, the blood is prevented from wasting when small 




Fig- 33- 

External View op the Heart.— 1. Right Auricle, 2. Left Auricle. 3. Eight Ventricle. 4. 
Left Ventricle. 5. Systemic Veins. 6. Pulmonary Veins. 7. Aorta. 8. Pulmonary Artery. 9, Coronary 
Vein and Artery, 

blood-vessels are cut or broken. Coagulation is the great 
safe-guard against bleeding to death from hemorrhage from 
the nose or lungs, because it inclines to thicken the blood 
and to form a coating over the broken vessels so as to stop 
the flow of blood. 

72. The organs of circulation are the heart, arteries, 
capillaries, and veins. 

The heart is a double muscular organ, having four 
cavities, two on each side of an unbroken partition. This 



68 



PHYSIOLOGY. 



partition divides the heart into a right and a left side. The 
two cavities on either side are known as auricle and 
ventricle. The auricles are the upper cavities, and the ven- 
tricles the lower. By this arrangement there are a right 
and left auricle, and a right and left ventricle. In Fig. 33, 
we have a front view of the heart, about one half the 
natural size. 

73. The passages of the heart are of three sets, as 
follows: (1) There are openings into the auricles, so that 

the blood may flow into the heart; (2) 
openings at the bottom of the auricles, 
by which the blood passes down into 
the ventricles; and (3) openings out of 
the ventricles, through which the blood 
leaves the heart. The first openings 
are constantly open, so that the blood 
may flow in at all times ; the second 
set are alternately opened and shut by 
door-like valves, which swing apart to 
let the blood pass down from the auri- 
cles into the ventricles, but which close 
again to prevent it from passing back ; 
the third set are guarded by semi- 
circular folds, which permit the blood 
to be forced out of the ventricles into the large tubes lead- 
ing from the heart, but close promptly, to stop it from run- 
ning back into the heart when the ventricles open to be 
filled again. By this arrangement, the blood enters the 
auricles of the heart in two constant streams, and is thrown 
out in two opposite streams from its ventricles. See Fig. 34. 

74. The Action of the Heart. — The two sides of the 
heart move together as one body in the following manner : 
The blood streams into both auricles until they are full, the 
right being filled by the returning blood from the system, 
and the left, by the pure blood from the lungs. The valves 




Fig. 34- 

Diagram of the Passages <>i 

the Heart. — 1. Left Auricle. 2 
Left Ventricle. 3. Right Auricle 
4. Right Ventricle. 



CIRCULATION. 69 

which form the bottom of the auricles now open, and each 
ventricle is immediately filled by the blood from the auricle 
above it. The ventricles now contract with great power, by 
which movement the valves into the auricles are instantly 
closed, and the blood within the ventricles is forced with 
great violence into the passages leading away from the 
heart. The left ventricle forces its contents into the great 
tube, called the aorta, which leads to all parts of the body. 
The right ventricle forces its blood into a large tube, 
called the pulmonary artery, leading to the lungs. While 
the ventricles have been contracting, the auricles have 
again filled, so that, as the ventricles relax, they are again 
filled, and immediately repeat their former action. In this 
manner they alternately contract and relax, work and rest, 
during the whole of life. This action is called the beating 
of the heart. The frequency of the beating is tested by 
feeling the heart as it strikes against the chest, or by hear- 
ing the "beats," which are caused by the closing of the 
valves. 4 If the fingers are placed lightly on the "pulse," 
at the wrist, the beating may be counted. Under ordinary 
circumstances, the heart contracts about seventy-two times 
per minute. 5 The time occupied in contraction is less than 
two thirds of the whole interval of one beat, so that the 
muscles of the heart rest more than one third the time. 
Although the seasons of rest thus gained are extremely short, 
they amount to more than eight hours daily. 

75. The arteries are the tubes that conduct the blood 
from the heart. They subdivide into a vast number of small 
branches, so as to convey the blood to every part of the 
system. The pulmonary artery receives the blood from" the 
right ventricle, and distributes it to the lungs to be purified. 
The aorta receives the blood from the left ventricle and 
supplies it to the tissues of the body for their nourishment. 
The arteries are formed of very tough, elastic substance, 
and, when empty, resemble rubber tubes. The arteries have 



7° 



PHYSIOLOGY. 




Fig. 35- 



a smooth lining, and are comparatively straight, so as not 
to lessen the force given to the blood by the heart. They 
are placed near the bones, and pass beneath 
the great muscles, in order that they may 
be shielded from danger. When they are 
cut or injured, there is great danger of 
bleeding to death. The blood in the 
arteries flows in jets, because of the beat- 
ing of the heart. In Fig. 35, we see a 
portion of a large artery. In the lower 
part of the figure^ the artery is represented 
as cut open, to show the absence of valves. 
76. Capillaries. — The minute, hair-like 
tubes, into which the arteries finally divide, 
are called capillaries. See Fig. 36. They 
are so extremely small that they are visible 
only by the aid of the microscope. They 
of an inch in diameter. The skin, except- 
is so full of these tiny vessels, that the 
point of a needle can not enter it without breaking some 
of them so that the blood flows out. The other membranes 
of the body are full of them in 
like manner. The walls of the 
capillaries are extremely thin — 
so very thin that the serum of 
the blood readily flows directly 
through these coats and bathes 
the various tissues in which the 
capillaries lie. It is in this way 
that the nourishment of the blood 
comes in contact with the por- 
tions that need it. The cor- 
puscles do not pass through the 
coats of the capillaries, but are 
capillaries. 



are about 
ing 



3000 

the cuticle, 




Capillary 



Fig. 36. 

laries.— 1. Vein. i. Artery, 3. 



carried along within the 



CIRCULATION. 



71 




Fig. 37- 
A Portion of Vein. 



77. The veins begin in the capillaries. By uniting into 
larger and larger tubes, the veins con- 
duct the blood back to the heart. The 
pulmonary vein empties the pure blood 
from the lungs into the left auricle. 
The returning blood from the system 
is poured into the right auricle. The 
walls of the veins are thin and are 
chiefly formed of 
muscle. On the in- 
ner surface of the 
veins, there are many 
folds, which serve as 

valves, to permit the 
blood to flow only toward the heart. Fig. 
37 represents a portion of a vein, laid open 
so that we may see the valves. 

The veins are usually nearer the surface 
than the arteries are, excepting the large 
veins, which are located deep in the body. 
They are larger than the arteries, and more 
crooked. The blood flows through them 
in a gentle, regular current. 

78. The Circulation Traced.— If a 
drop of blood be followed through the 
system, we may trace it, through the fol- 
lowing ideal course : (1) It enters the 
heart at the opening into the right auricle, 
(2) passes through the tricuspid valve 
into the right ventricle, (3) is forced out 
through the semi-lunar valves into the 
pulmonary artery, (4) circulates through 
the capillaries of the lungs, and returns to 
the left auricle by way of the pulmonary 

vein, (5) passes through the mitral valve into the left 




Fig. 38. 

1. Capillaries of lungs. 
2. Capillaries of system. 



72 



PHYSIOLOGY. 



ventricle, (6) is forced out through the semi-lunar valves 
into the aorta, (7) circulates through the capillaries of the 
system, (8) and returns to the right auricle of the heart by- 
way of the veins. In Fig. 38, the dark portion represents 
the venous blood. By following the course of the arrows, 
the pupil may readily trace the circulation from any point 
in the diagram back to the same point. 

79. The Pulmonary Circulation. — The blood passes 
from the heart to the lungs, to be purified by the air that 
is breathed. By this means the blood loses its gaseous im- 
purities and some water, and gains a fresh supply of new 
gases to be carried to the system. This is called the pul- 
monary circulation. Every drop of blood must pass through 
the lungs and return to the heart before it is sent out to 
nourish and purify the tissues. 

80. The Systemic Circulation. — The pure blood is 
distributed to the entire body by the aorta and its branches, 
after which it returns to the heart. This is called the sys- 
temic circulation. 6 

81. Assimilation. — It is by the passage of the serum 
through the walls of the systemic capillaries that the food 
is brought to the growing cells of every tissue. How each 
kind of tissue takes from the blood the particular kind of 
matter needed for growth and repair, we do not know. It 
is true, however, that bone takes just such kinds of sub- 
stance as are needed to make bone, and the muscles, 
cartilages, and nerves select what is necessary for them. 
We do not know how each tissue uses its proper nourish- 
ment for growth, and to repair the waste portions of the 
body. This intricate and unknowable process of nourish- 
ment is called assimilation. Assimilation is evidently the 
crowning purpose of both digestion and circulation. As- 
similation takes place most rapidly during rest, especially 
during the unbroken quiet of sound sleep. 

82. Removal of Waste Matter. — Not only does the 



CIRCULATION. 



73 



blood nourish the tissues, as 
just stated, but it is as much 
the purpose of the blood to re- 
move the waste matter. The 
blood changes the worn-out par- 
ticles to a soluble form, and 
absorbs them into itself as it 
flows through the tissues. The 
impurities are finally removed 
from the blood. 

83. The Lymphatics. — 
The fluid that passes out of the 
systemic capillaries into the sur- 
rounding parts, returns to the 
veins by two methods of absorp- 
tion : (1) much of it returns by 
being re-absorbed through the 
walls of the capillaries and mi- 
nute veins; (2) there are special 
tubes for absorbing this fluid, 
called lymphatics. The lym- 
phatics have their outer ends 
in almost all parts of the sys- 
tem, and by leading toward the 
heart they unite, and finally pour 
their contents into the large 
veins. See Fig. 39. These tubes 
are of extreme delicacy of struct- 
ure, so that absorption readily 
takes place through their coats. 
They have valves in them which 
permit their contents to flow 
only toward the heart. Fig. 31 
represents the end of a lym- 
phatic, as it does the end of a 



Fig. 39- 

Superficial Lymphatics of the Right 
Arm.— 1. Vein. 2. Lymphatic tubes. 3. 
Lymphatic glands. 



74 



PHYSIOLOGY. 



lacteal. In time of hunger and starvation, the lymphatics 
suck up the fatty portions, and enable the individual to 
live for a long time on his own flesh and fat. 7 The lym- 
phatics that have their origin in the lining coat of the 
alimentary canal, are called lacteals. 

84. Hygiene of Circulation. — The body is designed 
to be active. Proper exercise of its parts is favorable to 
proper circulation of the blood. Especially does exercise 
of the voluntary muscles promote increased circulation. 
The muscles, in contracting, press on the veins and force 
the blood toward the heart, w T hile the relaxation of the 
muscles permits the veins to fill again from the capillaries. 
Exercise causes the heart to beat faster, and the whole 
circulation to be quickened. 

Exercise increases the demand for nourishment. More 
food is needed, the appetite is sharpened, and the digestion 
is improved. The more thorough the flow of blood through 
the tissues, the more perfectly is the waste matter removed 
from the body. Hence, proper exercise promotes assimila- 
tion, and facilitates the prompt removal of waste material. 
These two processes, when fully performed, are the very 
essence of health and vigor. 

Exposure to the sunlight and fresh air also enlivens the 
flow of blood, and improves the quality of the blood. 
Close-fitting garments, and tight bands about the waist, 
neck, and extremities, tend to stop the proper flow of the 
blood. They should be carefully avoided. Tight garters, 
or shoes laced closely about the ankles, make the feet 
cold by arresting the flow of blood. 

The circulation is often seriously interrupted by sudden 
changes to cold temperature, or by exposure of some part 
of the body to draft of air. The circulation may be injured 
by getting the clothing wet, or by suddenly cooling after 
exercise. Such changes in the circulation tend to cause 
''chill" and to produce inflammation, resulting in "cold." 



CIRCULATION. 



75 



When, by accident, blood vessels are cut, the flow of 
blood may be stopped by pressure upon the wound. If an 
artery is cut, the blood will flow in jets, and will be of a 
bright red color. In such a case, pressure needs to be 
made by a tight band between the wound and the heart. 
If veins only are cut, the blood will flow regularly, and 
will be dark red, in which case pressure needs to be made 
beyond the cut. 

Fainting is caused by want of blood in the brain. In 
case a person should faint, place him in a horizontal posi- 
tion, with his head low. More blood will then flow to 
the brain, and the fainting will be relieved. 8 



Notes. 

i. The Composition of the Blood. — The following outline 
shows the composition of the blood : 



Blood. 



Corpuscles 



Plasma. 



Colored. 



Colorless 



Fibril 



Albumen. 



Clot of Coagulated Blood. 



Water. 

Salts. 
Soluble Food. 



7 6 PHYSIOLOGY. 

2. The blood corpuscles are of the form of discs, or flattened 
drops. They are about ^^ of an inch in diameter across the 
disc, and one fourth as much in thickness, being thinnest in the 
middle. The colorless corpuscles are fewest in number, being one 
to every three hundred of the colored corpuscles. The colorless 
are larger than the colored. To see the corpuscles, place a drop 
of freshly drawn blood on a clean microscopic slide ; lay on a piece 
of thin glass, to spread the drop, and put the slide under a power- 
ful objective. The corpuscles may be seen moving about in the 
plasma. 

3. Coagulation. — When blood is exposed to the air, it separates 
into two parts — the clot and the serum. This separation is caused 
by the coagulation of the fibrine. As the fibrine becomes solid, its 
fibers entangle the corpuscles, and strain them out of the serum, 
leaving the latter quite clear. The corpuscles and the fibrine form 
the clot. 

4. The Sounds of the Heart. — By putting the ear close to the 
chest of another, we may hear the beating of the heart. There are 
two kinds of sounds: (1) A sound longer in duration, and lower in 
pitch, heard over the ventricles; (2) a shorter, sharper sound, heard 
most plainly over the base of the heart. It is thought that the 
first sounds are caused by the sudden closing of the valves between 
the ventricles and auricles ; and the second, by the closing of the 
semi-lunar valves at the entrance to the large arteries. Expert 
physicians can determine much about the diseased condition of the 
heart by the character of the sounds. 

5. Rapidity of Heart-beat. — The causes that produce more rapid 
beating are exercise, warmth, rich food, stimulating drinks, and 
excitement. In fever the heart beats rapidly. As a person grows 
feeble from any cause, the beating usually grows more rapid, but 
less powerful. When awake, the pulse is considerably faster than 
while asleep, and, in standing, it is more rapid than while lying 
quietly. 

6. Portal Circulation. — The blood that returns from the ali- 
mentary canal passes through the liver before reaching the heart. 
This is called the portal circulation. The veins from the stomach 
and intestines lead into one large vein (the portal vein) that enters 
the liver. This vein divides, to form the capillaries of the liver. 
Having passed through the liver, the blood flows into the large 
vein that empties in the heart. The changes that occur in the 
blood as it passes through the liver are not fully known. The 



CIRCULATION. 



77 



bile is secreted from the blood, and the amount of sugar in the 
blood is increased by the circulation through the liver. 

7. Absorption. — In recent years, there have occurred many cases 
of remarkable "fasting," in which persons have lived without solid 
food for forty days or more. Such persons drank water to maintain 
the fluidity of the blood, while they lost in weight at the rate of a 
pound (more or less) per day by the absorption of their fat and 
other tissues. Such persons ate themselves during the time of their 
fasting. 

8. Headache. — If too much blood flows to the brain, dizziness 
and headache may result therefrom. If headache results from 
such a cause, moderate exercise of the muscles will tend to relieve 
it, by causing less blood to flow to the brain. If headache results 
from impurity of the blood, exercise will in like manner tend to 
relieve it. 



Suggestive Questions. 

What are the great purposes of the circulation of the blood ? 
What is the blood of a tree? What is the composition of the 
blood? What is the use of the corpuscles? How is the blood 
itself nourished ? Which part of the blood carries all the other 
parts ? W T hy are the large arteries seldom cut ? Why may we 
compare the heart to an engine? What is a heart-beat? What 
causes the blood to return to the heart ? Why is the left ventricle 
strongest ? 

Of what is the heart made ? How is the heart nourished ? How 
may we cause the heart to beat more rapidly ? What are capil- 
laries ? What changes occur to the blood in passing through the 
coats of the alimentary canal ? What changes occur to the blood 
in the tissues ? How may exercise relieve headache ? What are 
lymphatics? What are the effects of exercise upon the blood? 
Why does brisk exercise in the open air cause hunger? Why do 
we need extra clothing while asleep ? Why does starvation or 
sickness cause one to become thin? Why should we not remove 
coat or shawl just after exercise, in order to "cool off?" How are 
the circulatory organs injured by tight lacing? Why will a hot 
foot-bath tend to relieve headache ? Why do students suffer with 
cold feet ? 



78 



PHYSIOLOGY. 



Topical Outline. 



Circulation. 


I. Definition. 


(1) Structure. 


2. General Plan. 


(a) Cavities. 


3. Purposes. 


(b) Passages. 


a. To Nourish. 


(2) Action. 


b. To Purify. 


b. Arteries. 


c. To Warm. 


c. Capillaries. 


4. The Blood. 


d. Veins. 


a. General Character. 


6. Complete Circulation. 


(1) Appearance. 


7. Pulmonic " 


(2) Amount. 


8. Systemic " 


b. Composition. 


9. Assimilation. 


(1) Corpuscles. 


10. Removal of Waste Matter. 


(a) Colored. 


11. Lymphatics. 


(b) Colorless. 


12. Hygiene. 


(2) Plasma. 


a. Effects of Exercise. 


(a) Serum. 


b. Effects of Air and Sunlight 


(b) Fibrine. 


c. Effects of Chill. 


3. Organs. 


d. Accidents. 


a. Heart. 


e. Fainting. 



CHAPTER IX. 

RESPIRATION. 

85. Demand for Air. — It has been shown that the 
body constantly requires to be nourished by food, and that 
this food must be circulated to all of the parts by the blood. 
But the body can not live by these processes alone, how- 
ever rich the food, or perfect its digestion and circulation. 

All living things require^ the action of another very im- 
portant element. They demand the presence of the air, 
and require that some portion of it shall constantly 
enter their blood, as food does, and be circulated to 
their parts. Just as all living things must have food to eat, 
and water to drink, so must they have air to breathe. No 
other want is more urgent than this demand for air. Men 
may live for weeks without solid food, and may live for 
several days without water, but the absence of air, for even 
a few minutes, causes death. 

The plants spread their leaves in the air and sunlight, 
and take what they need from the atmosphere through the 
great surfaces thus exposed. Fishes obtain air, by means 
of their gills, from the water in which they swim. The 
higher animals that live in the air, take it into their blood 
through very thin membranes, arranged in the chest, called 
lungs. The process by which the air passes in and out of 
the blood is called respiration. 

(79) 



80 PHYSIOLOGY. 

86. What the Air Does. — The part of the air that is 
thus taken does not form new tissues, as bread and meat 
do, hence, in this sense, air is not food. The air thus taken 
performs other important uses, as follows : (i) It aids in 
preparing the food for assimilation ; (2) it acts upon the 
food in the blood to cause the warmth and vigor of the 
body; (3) it changes the worn-out particles of the tissues, 
so that they may be absorbed by the blood and be swept 
out of the system. More briefly stated, the purposes of 
respiration are: (1) to warm, and (2) to purify the body. 

87. The General Plan of Respiration. — The chest, 
in which the lungs are placed, is open to the external air 
by a set of passages connecting with the nose; by the 
action of certain muscles, the chest is enlarged, so that the 
air rushes in, and, after a short interval, is made smaller 
again, so that the air is forced out. By repeating these 
changes in the size of the chest, the air alternately passes 
in and out of the lungs. 

The air in the lungs is separated from the blood by a 
very thin, moist membrane. The air readily passes through 
this thin membrane into the corpuscles of the blood. The 
air is then whirled away by the blood to every portion 
of the body. 

88. The air surrounds the body, at all times, in the 
form of an invisible, odorless, tasteless gas. It forms a 
vast ocean of fluid, enveloping the earth to the depth of 
many miles. It is best known to the senses when it moves 
in a strong wind. It is the air that sways the tops of trees, 
supports the birds in their flight, and that bears up the 
clouds. 

The air is a mixture of several gases. The four principal 
parts of the air are oxygen, nitrogen, carbonic acid, and 
watery vapor. 

89. Oxygen forms about one fifth of pure air. It is 
the oxygen that unites with substances to burn them. It 



RESP1RA TION. 



81 



is the oxygen that enters the corpuscles and causes the 
warmth of the body. 

90. Nitrogen forms about four fifths of the air. Nitro- 
gen does not unite with things to burn them, nor does it 
support life. Its great service to man is that it dilutes the 
oxygen, which would be too rich and active if the air were 
composed of it alone. Nitrogen is not poisonous. 

91. Carbonic acid gas forms a very small part of 
pure air. Carbonic acid gas is produced by all kinds of 
combustion, by the decay of organic matter, and by the 
breathing of animals. It aids in supporting the growth of 
plants. It is not poisonous, 
but destroys animal life by 
causing suffocation. 1 

92. Watery vapor, 
which is water in the form 
of gas, is a very small part 
of the air. It is constantly 
evaporating from bodies of 
water, and from the moist 
earth. It is also produced 
by the breathing of animals. 

93. The organs of res- 
piration are the air pas- 
sages, the lungs, and certain 
muscles that cause the 
breathing. 

94. The air-passages 
are: (1) The nasal open- 
ings, which lead back to the 
pharynx; (2) the larynx, a short, cartilaginous box, in which 
the voice is produced; (3) the the trachea, or wind-pipe, 
leading from the larynx to the central part of the chest; 
(4) the branches formed from the trachea, called bronchial 

tubes. The bronchial tubes subdivide until, finally, they 
Pgy.-6. 




Fig. 40. 

Ideal Diagram of Lungs and Air-passages. 



82 



PHYSIOLOGY. 



end in clusters of tiny sacks, called air-cells, which form 
the inner and closed ends of the air -passages. In Fig. 40, 
we see a diagram of the lungs and air-passages, with the 
larynx at the top of the figure, the trachea leading down- 
ward and dividing into many branches. The dark portion 
of the figure, to the right, represents the left lung entire. 
On the opposite side, the substance of the right lung is 
removed to show the manner in which the bronchial tubes 
subdivide. 

95. The Trachea and Bronchial Tubes. — The trachea 
is a membranous tube, some four or five inches long, and 
less than an inch in diameter. It is 
formed mainly of cartilaginous C-shaped 
rings, placed one above another, with 
the open part behind. These rings 
keep the trachea open. The bronchial 
tubes are similar to the trachea in 
^&^*x structure, but they are smaller and 

have thinner walls. The air-cells 
have extremely thin membranous walls, 
which separate the air within them from 
the blood in the capillaries of the lungs. 
There are many millions of cells, so 
that their entire surface for the absorp- 
tion of the air is very great. Fig. 41 
shows how the bronchial tubes end in clusters of air-cells. 
The lining of the air-passages is very sensitive, especially in 
the larynx and trachea, so that any foreign body that may 
be drawn into them causes pain and violent coughing until 
it is expelled. The lining of the bronchial tubes is covered 
with a peculiar hair-like kind of cells, called cilia, which 
aid in removing dust from the lungs. 

96. The lungs are two large, soft lobes that fill the 
chest. The lungs are formed of the bronchial tubes and 
air-cells, and of the blood-vessels of the pulmonic circula- 




Fig. 41. 

Cluster op Air-cells 
End of Bronchial Tube. 
Cell. 



RESPIRATION. 



83 



tion. Soft, fibrous tissue fills between these various tubes, 
to support and bind the whole together. These two great 
sets of passages, the one for the air, the other for the blood, 
are arranged as closely together as possible, so as to expose 
the blood to the action of the air. The outside of the lungs 
is covered with a delicate membrane, called the pleura. 
This smooth membrane also lines the inner surface of the 
chest. In all movements of the lungs these two smooth 
membranes rub together, so that all friction 
is avoided. 

97. The movements of the chest, 
that cause the air to flow in and out of 
the lungs, are produced by the action of 
the diaphragm and intercostal muscles. 
The diaphragm is a thin, broad, circular 
partition across the body, separating the 
abdomen from the chest. It forms the 
bottom of the chest, and is arched upward, 
like an inverted saucer, fitting closely 
under the lungs. Its outer edge is fast- 
ened to the walls of the body, with the 
muscular fibers extending inward toward 
the center. When these fibers are contracted, the diaphragm 
is pulled down and made more nearly level. This causes 
the cavity of the chest to be made larger. At the same 
time, the intercostal muscles, whose fibers fill the spaces 
between the ribs, contract and lift the ribs upward and out- 
ward, causing the chest to become broader. By these two 
actions, the chest is made larger in all directions. This 
enlargement causes the air to flow into the lungs, and the 
action is called inspiration. The fully expanded chest is 
represented in the ideal section, Fig. 42. 

When these muscles relax, the elasticity of the parts that 
have been pulled out of the shape, causes them to return to 
their original form and position, so that the chest becomes 




Fig. 42. 

Inspiration.— 1. Dia- 
phragm. 2. Sternum. 



8 4 



PHYSIOLOGY. 




smaller. This action forces a part of the air out again, and 
is called expiration. In Fig. 43 we see the chest repre- 
sented at the close of an expiration. 

The lungs at all times fill the chest, and at all times 
contain air. Their capacity at time of 
full inspiration is about one gallon, and 
at time of expiration twenty to thirty cu- 
bic inches less. With each breath, about 
a pint of new air enters the lungs, to mix 
with what is already there, so that, in ex- 
haling, some of the old air passes out. 2 
The air of the lungs is constantly mixing 
and changing with that which is being 
breathed, so that air in the lungs is entirely 
renewed in a short time. By this arrange- 
ment, the air that is next to the blood is 
not suddenly changed, and the fresh, cold 
air does not come in contact with the sur- 
faces of the air-cells. 

The frequency of respiration depends upon the rapidity 
of the circulation of the blood. Usually, there are from 
seventeen to twenty inspirations to the minute. If the cir- 
culation is increased, the breathing is usually more rapid. 

98. Changes in the Air and Blood. — While the air 
is in the lungs, a large portion of the oxygen of the air enters 
the blood, so that, after being in the lungs, the air will not 
support combustion, nor is it fit to be again breathed. While 
the air is in the lungs, it receives three substances from the 
blood, namely: (1) Carbonic acid gas, (2) watery vapor, (3) 
organic matter. The presence of these substances in the 
exhaled breath may be shown as follows : by breathing into 
a glass containing some lime-water, a milky sediment will be 
formed in the water by the carbonic acid contained in the 
breath; by breathing on a cold pane of glass the vapor of 
water of the breath will be condensed into a film of water 



RESPIRA TION. 85 

on the glass; by breathing into a bottle, and keeping such 
breath confined for a short time, a bad odor is developed in 
the vessel by the organic matter of the breath. 3 

The changes that occur in the blood by respiration are 
quite evident from the changes produced in the air. The 
blood that passes to the lungs through the pulmonary artery 
is the dark, impure, venous blood that has just returned to 
the heart from the system. In passing near the air-cells in 
the lungs, the blood receives the oxygen of the air, and 
gives off some of its carbonic acid, water, and organic im- 
purities. The color of the blood is changed from a dark, 
bluish hue to a bright scarlet color. It returns to the heart 
greatly purified. 

99. The Function of the Air in the Blood. — It is 
mainly the oxygen of the atmosphere that enters the blood 
corpuscles in their passage through the lungs. This oxygen 
is distributed throughout the system, and unites with the car- 
bonaceous food, and other substances, in the capillaries and 
tissues. By this union, a slow combustion occurs, by which 
heat is liberated to the surrounding parts, much as heat is 
caused by an ordinary fire. The products of this.- combus- 
tion are carbonic acid gas, water, and various salts, all of 
which are left in the blood as impurities. 

The oxygen also consumes the waste tissues of the body, 
thereby causing more heat, and producing more impurities 
in the blood. It is in this way that oxygen serves as the 
direct agent in warming and cleaning the body. 

Mr. Huxley speaks of oxygen as "the sweeper of the 
living body." 

100. Hygiene of Respiration. — Since respiration af- 
fects immediately the purity of the blood, it is evident that 
the health of the body must be greatly influenced by the 
kind of air breathed, and by the fullness of respiration. 

101. Ventilation. — The outdoor air is pure. It con- 
tains the proper amount of oxygen, and the other com- 



S6 PHYSIOLOGY. 

ponents are so completely diffused that they are not injurious. 
The air of dwellings is generally deficent in the amount of 
oxygen, and contains various impurities. This difference 
exists, (i) because the air of houses is not sufficiently free 
to circulate with the outdoor atmosphere, and (2) because 
it receives the gases thrown off as impurities from the bodies 
of those who live within, together with the impurities arising 
from heating, lighting, cooking, etc. Especially does the 
air of sitting-rooms and sleeping apartments, of school-rooms 
and factories, of churches and public halls, contain an excess 
of carbonic acid gas and organic matter, while the oxygen 
is speedily reduced below the proper amount. The process 
by which the foul air of rooms is replaced by fresh air is 
called ventilation. 

The organic impurities thrown off from the lungs and 
skin are of the most noxious character. Air containing such 
impurities is wholly unfit to be breathed again. Especially 
is this true of the air thrown off from persons afflicted with 
disease. For this reason, both for the sake of the individual 
who is sick, as well as for the safety of the attendants, rooms 
containing diseased persons should be most carefully venti- 
lated. Sleeping-rooms need to have the sunlight and fresh 
air freely admitted during the day, and at night they should 
have sufficient openings at windows and transoms to permit 
change of air. An open fire will ventilate a sitting-room, 
while if closed stoves and heaters are used, there must be 
other ventilating openings beside those of the cracks of doors 
and windows. It is better to consume more fuel than to 
shut off the avenues of pure air for the sake of keeping 
warm. Just as the air is continually rendered impure, so 
should there be adequate means for its constant removal 
and renewal. The morbid effects of impure air frequently 
produce restlessness, irritability, dullness, headache, and 
loss of appetite. Long continued exposure to impure air 
results in painful and fatal diseases. 4 



RESPIRATION. 87 

Since the air within is warm, openings made near the top 
of the room will both permit the impure air to escape, and 
the fresh air to enter. Small openings that can remain open, 
at the top and bottom of the room, on opposite sides, may 
produce constant change of air without causing an injurious 
draught. In any case there must be sufficient openings for 
the air to pass in and out. 5 

102. Manner of Breathing. — Beside the precaution 
concerning the purity of air, much attention needs to be 
given to the manner of breathing. The amount of air 
taken is quite as important as its purity. The chest requires 
free movement, that sufficient air may enter the lungs. The 
lower portion of the chest is naturally largest and most 
yielding as a means of full and deep respiration. Many 
persons, however, lace this part of the chest so tightly as to 
wholly deform it, making the lower portion more slender 
than the portion above, and robbing the chest of all freedom 
of motion. By this deformity, the liver and stomach are 
crowded downward into the lower part of the abdomen, and 
the lungs are greatly diminished in volume and breathing 
capacity. Upon no other part could continued pressure be 
made that would be so fatal to the health. 

The lungs are quite as often and as seriously injured by 
habitually sitting or standing in such position that the chest 
is cramped and the breathing is limited and feeble. Stooped 
shoulders and hollowed chest are deformities that are ex- 
tremely ungainly in appearance, and that tend to cause weak 
lungs. By persistent attention, a person may acquire the 
habit of holding the shoulders back, and, by full breathing, 
may permanently increase the capacity of the lungs to a very 
great extent. The erect position and full chest are typical 
of health and strength. There are three features of correct 
breathing that no one can afford to neglect : (1) Breathe pure 
air; (2) give the chest free motion; (3) maintain erect form 
and full inspiration. 



88 



PHYSIOLOGY. 



103. The Voice. — The 

vibration of the vocal cords. 



In breathing, the proper opening for the passage of the 
air is the nose. The mouth is not an air-passage. It is 
quite injurious to the throat and lungs to breathe through 
the mouth. One should be careful to sleep with the 
mouth closed. 

voice is produced by the 
These cords are located in 
the larynx. -The larynx is sit- 
uated at the upper end of the 
neck, and forms the air-pas- 
sage from the pharynx to the 
trachea. The large prominence 
that may be seen or felt just 
below the lower jaw, on the 
front part of the neck, is the 
larynx. See Fig. 44. The 
larynx is a cartilaginous box, 
about two inches long, and 
more than an inch in breadth. 
Its walls are formed of four 
plates of cartilage, that so fit 
upon one another that we may 
readily change the shape and 
size of the larynx. 
The interior of the larynx is lined with mucous membrane. 
This membrane is very sensitive, so that violent coughing is 
caused if anything touches it. The larynx is closed at the 
top by the epiglottis, a long piece of cartilage that is attached 
to the base of the tongue. The epiglottis closes over the 
larynx while we swallow, and at other times is raised, so 
that the larynx is open for the passage of the air to and 
from the lungs. 

104. The Vocal Cords. — The vocal cords, by which 
the sound is made, are within the larynx. They are not 
strings, but are simply folds of the mucous membrane that 




Fig. 44- 

External View of the Left Side of 
Larynx.— 1. Front portion of hyoid bone. 2. 
Upper edge of larynx. 3. Lower portion of 
larynx. 4. Second ring of trachea. 



RESPIRATION. 



89 




Cross Section of the Larynx above the 
Vocal Cords.— 1. Right vocal oord. 2. Left 
vocal cord. 3. Cartilages to which the vocal 
cords are attached behind. 4. Front edge of 
the larynx. 



lines the larynx. These folds are on the sides of the larynx. 

There are four folds, or cords, 

7 ' 4 

two above, one on each side, 
called the false cords, and two 
below, one on each side, called 
the true cords. Their edges 
are smooth, and are quite 
sharp. When sound is being 
made by them, they nearly 
meet across the larynx. 

105. How the Voice is 
Made. — During ordinary 
breathing, no sound of the 
voice is made ; in such cases, 
the cords are not stretched 
tightly across the opening of 
the larynx, but are relaxed, 
and the air passes through the 
larynx without obstruction. In order to make a sound, we 
draw the cords tightly, and, by stretching them, make them 
draw close together, so as to nearly close the passage of air 
through the larynx. Their edges almost touch, and are thin 
and tight. While in this condition, we force the air between 
them, and thus cause the edges of the cords to vibrate very 
rapidly. The vibrations of the cords and of the air surround- 
ing them produce sound. We change the sound by the way 
in which we stretch the cords, and by the size and shape we 
give to the larynx and mouth. If the cords are drawn very 
tight, they vibrate more rapidly, producing an acute sound ; 
if they are more loose, and are thicker, they produce a sound 
that is more grave. 

The loudness of the voice depends upon the force with 
which the cords are caused to vibrate. This depends almost 
wholly on the power with which the breath is forced out of 
the lungs. To have a full, round, strong voice, one needs 



po 



PHYSIOLOGY, 



to have a full, strong chest and diaphragm, and to speak with 
plenty of air in the lungs. 

The articulation of sounds, by which we are enabled to 
speak, is performed by the lips, tongue, and teeth. The 
quality of the voice, or that peculiar property of it by which 
we recognize the voice of any person, depends upon the 
shape of the chest, trachea, larynx, and nasal cavities. 

The power or force of the voice may be very greatly 
developed by proper exercise and training of the vocal 
organs. Any one who will give the lungs their natural free- 
dom, and will breathe deeply and fully, may speak in a loud 
tone. The weak voice is usually indicative of inefficient 
breathing. The purity of the tone and clearness of articu- 
lation may be greatly improved by intelligent practice. By 
practicing upon the elementary sounds of words, the most 
difficult combinations of sounds may be mastered. Singing 
and reading aloud are most excellent exercises for develop- 
ing the voice. The lungs, too, will gain in power. One 
who sings or speaks much will not be likely to suffer from 
weak lungs. 

Notes. 

i. Carbonic Acid. — The amount of carbonic acid in the atmos- 
phere of different regions has been estimated about as follows: 

Open air of country 4 in 1000 parts of ai 

" " " city 5 " 

In school-room, ventilated 2. " " 

In school-room, not ventilated. . .30. " " 

In bed-room, before airing 5. " " 

In bed-room, after airing 1. " " 

In exhaled air 40. " " 

In air causing distress 5- " " 

2. Volume of Lungs. — The following estimates have been made 
of the capacity of the lungs: 



RESPIRA TION. 



91 



Residual air that can not be exhaled 100 cubic inches. 

Reserve air that is not ordinarily exhaled 100 " 

Tidal air of ordinary respiration 25 " 

Complemental air possible after ordinary inspiration. 1 15 " 

Ordinary capacity nearly 230 '•' 

Extreme capacity nearly 340 " 

The left lobe of the lungs is somewhat smaller than the right, as 
the heart lies somewhat more in the left side of the chest than in the 
right. 

3. The following table shows the principal changes produced in 
the blood by its passage through the lungs. 

Venous. Arterial. 

Oxygen ..... 8 per cent 18 per cent. 

Carbonic Acid 15 to 20 per cent 5 per cent. 

Color Dark blue Scarlet. 

Water More Less. 

4. Diseases of the Lungs. — The most common and fatal disease 
of the lungs is pulmonary consumption. This disease consists in 
actual disorganization of the substance that composes the lungs. It 
must lead finally to fatal results. Consumption occurs most frequently 
from heredity, in which children suffer weakness as a result of the 
diseased conditions of their parents. In such casess, it is almost 
impossible to avoid the fatal tendencies. Consumption may have 
its origin in injuries resulting from frequent heavy "cold;" or it 
may result from continu d impurity of the blood. The most robust 
person, if exposed to foul air for a long time, will finally yield to 
fatal tendencies to consumption. On the other hand, persons who 
have inherited the disease are comparatively safe from its ravages 
if they live sufficiently in the free air and sunlight, in regions in 
which the air is dry, and the changes in temperature are not great. 

Organic impurities thrown off from the lungs float in the air as 
noxious germs. Especially is this true of the matter that passes off 
from diseased persons. It is by breathing such matter that diseases 
are often contracted. The breath from one afflicted with consump- 
tion, scrofula, diphtheria, typhoid fever, or any other disease of such 
decided character, is wholly unfit to be rebreathed by any one. 

5. Ventilation depends on the movement of air in currents, caused 
by differences in temperature. Warm air, being lighter, rises, while 



02 



PHYSIOLOGY. 



cold air, being heavier, descends. Special contrivances for ventila- 
tion must admit fresh air and conduct away the foul air. This is 
usually accomplished by registers for admitting pure air near the 
upper part of the room, while the impure air is led away by con- 
ducting shafts from the lower part of the room. The passages for 
the exit of foul air should lead into warm flues or chimneys, so 
that there may be a sufficient upward current. The fresh air that is 
admitted need not be cold, but may be warmed before it enters. 
This may be done by passing it over heating surfaces. The air 
arising from cellars or sewers should in no case be allowed to enter 
the rooms of dwellings. Cellars should have openings for the escape 
of their air. 



Suggestive Questions. 

What are the purposes of respiration ? How does the need of air 
compare with the want of food? How do plants breathe? Why 
do all living bodies need air? What is the composition of the air? 
Why are carbonic acid and water found in the exhaled breath? 
How may we show the presence of carbonic acid in the exhaled 
breath ? How may we show water to be in the breath ? Why 
may we see the breath in frosty weather ? How is the body warmed ? 
What different structures compose the lungs? Why do we call the 
oxygen the "sweeper of the living body?" 

What changes are produced in the air by respiration? How 
does breathing alter the blood ? How do we cause respiration ? 
Why should we not make the beds early in the day ? What bene- 
fits come from an open fire? How may the power of the lungs be 
impaired ? How may the power of the lungs be increased ? Why 
should we wear shoulder-straps to support the weight of the cloth- 
ing? What part of the body needs the loosest clothing? How 
may we best ventilate a school-room? What evils result from 
stooped shoulders? W T hy are soldiers required to maintain the erect 
form and full chest? What conditions favor the development of 
consumption ? 

How is the sound of the voice produced? What are the vocal 
cords? How do we make different kinds of sounds? What do 
the lips, tongue, and teeth have to do with the voice? How may 
we speak in a loud tone? How may we strengthen the voice? 



RESPIRA TION. 



93 



Topical Outline. 



Respiration. 



I. Definition. 


c. Muscles. 


2. Universality of. 


(1) Diaphragm. 


3. Purposes. 


(2) Intercostal. 


a. To warm. 


7. Process. 


b. To purify. 


a. Movements. 


4. General Plan. 


(1) Inspiration. 


5. Air. 


(2) Expiration. 


a. General character. 


b. Changes. 


b. Composition. 


(I) In air. 


(1) Oxygen. 


(2) In blood. 


(2) Nitrogen. 


8. Hygiene. 


(3) Carbonic acid. 


a. Ventilation. 


(4) Watery vapor. 


b. Manner of breathing 


6. Organs of. 


9. Voice. 


a. Passages. 


a. Organs of. 


(1) Nasal openings. 


(1) Larynx. 


(2) Pharynx. 


(2) Vocal cords. 


(3) larynx. 


(3) Mouth. 


(4) Trachea. 


(4) Nasal cavity. 


(5) Bronchial tubes. 


b. How produced. 


(6) Air cells. 


c. How modified. 


b. Lungs. 


d. How cultivated. 


(1) Air tubes. 




(2) Blood tubes. 




(3) Connecting tissue. 




(4) Pleura. 





CHAPTER X. 

EXCRETION. 

1 06. The process by which the system is constantly 
cleaned, is known as excretion. Nutrition renews and 
builds up, excretion clears away and purifies. These two 
acts, taken together, form the one great process of life in 
the body. 

107. The Impurities. — The matter to be excreted is 
chiefly produced by the oxidation of food and waste tissue. 
This impure matter is formed in all parts of the system. 
The impurities are mainly carbonic acid gas, water, and 
various other substances, the most abundant of which is 
urea. These substances are all soluble in the blood, and 
are absorbed by it as it flows through the body. The 
blood, as it flows into the veins, washes these impurities 
from the various tissues into the veins. It is for this reason 
that the venous blood is impure, and it is in this way that 
the blood serves to clean the body. 

108. Organs of Excretion. — There are certain organs 
designed to remove the impurities from the blood. These 
are the lungs, skin, and kidneys. 

The structure of all of these organs is such that the 
blood, as it flows through them, is spread out over a vast 
(94) 



EXCRETION. 



95 



surface of capillaries. The walls of these capillaries are 
very thin, and separate the impure blood on the one side 
from open tubes and passages on the other side. These 
open tubes lead out to the air. Through this delicate 
partition the impurities pass from the blood, and are then 
cast out of the body. This arrangement has been explained 
in the structure of the air cells of the 
lungs and the perspiratory tubes of 
the skin. 

109. The kidneys seem specially 
designed to purify the blood. They 
perform no other purpose. The kid- 
neys are two in number, located in 
the back portion of the abdomen, one 
on each side of the spinal column, a 
short distance below the diaphragm. 
See Fig. 46. They are dark-colored, 
bean-shaped bodies, about two thirds 
as large as the closed fist. They are 
like the lungs, in being made of two 
kinds of vessels : (1) Blood-vessels, 
(2) exit tubes. Large branches of the 
aorta, called the renal arteries, con- 
stantly convey a portion of the blood 
to the kidneys. This blood passes 
through the capillaries of the kidneys, 
and is collected into the renal veins that return it to the 
large vein that empties into the right auricle of the heart. 
As the blood goes through the capillaries, its watery part 
strains through their thin walls, carrying with it the various 
salts and gases from the blood. The water and other im- 
purities pass out of the kidneys and collect in the bladder. 
See Fig. 47. With the average man, about fifty ounces of 
water and fifteen grains of urea are removed from the blood 
in this way daily. 1 




Fig. 46. 



Kidneys and their Vessels. — 
1. Left kidney. 2. Ascending 
vein. 3. Aorta. 4. Left ureter. 
5. Bladder. 




9 6 PHYSIOLOGY. 

The lungs excrete much carbonic acid and watery vapor, 
with scarcely a trace of urea. 

The skin excretes much water and 
salts, with very little carbonic acid. 

The kidneys excrete a great deal of 
water and salts, with but little carbonic 
acid. 

no. Hygiene of Excretion. — The 
activity of all the excretory organs is 
Fig. 47 . absolutely necessary to health, to arrest 

section op Kidney. -i. any one of them is fatal. The principal 

Bod v of Kidnev. 2. Internal . . 

vessels, s. ureter, leading to ways of preserving their healthy action 
are to breathe freely of pure air, to keep 
the skin warm and clean, and to take sufficient exercise 
to keep the blood in proper circulation. The effects of im- 
perfect excretion are languor, headache, loss of appetite, 
and inclination to fever. If the blood is not purified, the 
system becomes clogged, and the blood itself becomes loaded 
with the poisonous substances from the system. Diseases 
of the kidneys are of the most serious character. 



Note. 

i. Gains and Losses by the Blood. — The blood is constantly 
losing some of its parts, as follows: In passing through the lungs, 
it loses carbonic acid and water ; in the kidneys, it loses water, urea, 
and salts; in the skin, it loses water, urea, carbonic acid, and salts; 
in the liver, it loses bile and other substances; by the repair of the 
tissues, it loses nutritious matter ; by oxidation, it loses carbonaceous 
matter and oxygen ; by radiation, it loses heat. 

The blood is constantly gaining, as follows : In the lungs it 
gains oxygen ; in the skin, oxygen ; in the liver, sugar and other 
substances; from passing through the tissues, it gains impurities; 
from oxidation of food, it gains impurities ; by oxidation, it gains heat. 

The blood loses substances that are taken from it by the glands 
for secretions. 

The blood gains nutritious substance from the digestion of food. 



EXCRETION. 



97 



Suggestive Questions. 

What is meant by excretion? How is excretion related to nu- 
trition? What are the two great functions of the blood ? What is the 
origin of blood impurities? How are the impurities taken from the 
tissues? How are the impurities taken from the blood? What is 
the structure of all excreting organs ? What are the substances 
excreted ? 

Is it proper to say the blood is purified by the lungs? If not, 
what is better? What is the minute structure of the kidneys? 
How do they filter the blood ? Why is the blood in the upper 
portion of the ascending vein purer than that in the lower portion ? 
Why is the blood of the renal vein the purest blood in the body ? 
What conditions favor excretion ? How are the kidneys unlike the 
lungs and skin ? 

Topical Outline. 

Excretion. 



i. Definition. 

2. Purpose. 

3. Matter excreted. 

a. Origin. 

(1) Oxidation of carbonaceous 

food. 

(2) Oxidation of waste tissues. 

b. Kinds. 

(1) Carbonic acid gas. 

(2) Water. 

(3) Urea and uric acid. 

(4) Various salts. 



General Plan. 

a. Impurities 

blood. 

b. Impurities 

blood. 
Organs. 

a. Lungs. 

b. Skin. 

c. Kidneys. 
Hygiene. 



absorbed by 



excreted froi 



Pgy.-7. 



CHAPTER XI. 



THE NERVOUS SYSTEM. 



in. The organs of the body, such as the muscles, stom- 
ach, heart, and lungs, have no power of themselves to 
perform their important work. They are controlled and 
caused to work together by the nervous system. Through 
the nervous system we feel and move. It is through the 
nervous system that we think. 

The nervous system, as shown in Plate IV, has certain 
great central parts, from which great numbers of tiny lines 
are distributed to the various parts of the body. By these 
centers and lines, all parts of the body are controlled. 
112. The Character of Nervous Tissue. — The mat- 
ter of which the nervous sys- 
tem is formed is unlike any 
other in the body. Nervous 
matter is three fourths water. 
It is a soft, white, pulpy sub- 
stance, of extremely delicate 
structure. This nervous sub- 
stance is very sensitive to 
touch. Close examination with 
the microscope shows that nervous matter is of two kinds : 
(i) The greater portion is white matter; (2) the less portion 
(98) 




Fig. 48. 

Forms of Nerve Cells. 



THE NERVOUS SYSTEM. 



99 



is grayish or reddish. The white matter is in the form 
of long, tubular fibers, about 3-^0" °f an mcn m diameter. 
These are called nerve fibers. The nerve fibers are united, 
side by side, into cords, called nerves. The gray matter is 
in the form of tiny cells. These are called nerve cells. The 
nerve cells are collected into little knots or masses, called 
centers. Some of the nerve fibers begin in the skin and 
end in nerve centers ; others begin in nerve centers and end 
in the muscles. Some nerve fibers connect nerve centers 
with one another. Nerve fibers conduct 
impressions to and from the nerve cen- 
ters. The centers receive the impressions 
brought to them by the fibers, and send 
out impulses along the fibers leading from 
them. 

The simplest possible arrangement of 
nervous matter that can perform complete 
nervous action must consist of one or 
more cells acting as a center, with a fiber 
leading to it, and one leading from it. 1 

In the accompanying figure, c is the 
center, <?, the fiber leading to it; b, the 
fiber leading from it. If now the fiber a 
is irritated at the end /, the irritation is 
conducted to the center c. An impulse 
is now sent along the fiber b to produce 
motion in the muscle m. You may illus- 
trate nervous action by your own feelings 
and motions. If any thing touches your 
finger, the ends of the fibers in the finger 
are irritated. This irritation is conveyed 
to your brain and you feel the touch, 
impulse from the brain along the fibers leading to the 
muscles, and thereby move your arm. In this way you 
experience the complete action of nervous matter. 




Fig. 49. 

Element of Nervous 
System. — a. Sensory fiber. 
6. Motor fiber, c. Center. 
/. End of sensory fiber, to. 
Muscle. 



You now send an 



IOO 



PHYSIOLOGY. 



113. The general nervous system consists of two 
subdivisions : (1) That part which aids in thinking, feeling, 
and moving; and (2) that which is engaged in controlling 
the vital organs. The first division is called the cerebro- 
spinal nervous system • the second is called the sympathetic 
nervous system. 




The Rkain Seen Fro 



Fig. 50. 
-1. Great fissure. 2. Anterior lobes. 3. Posterior lobes. 



114. The cerebro-spinal system consists of the brain, 
the spinal cord, and the various nerves that connect these 
two with the skin and muscles. Through this system, we 
know when any thing touches us. Through this system, 
the mind learns the condition of the body. The mind 
controls the body through this system. 

115. The brain is the chief nervous center. It is 
located in the skull, and is connected with all parts of the 



THE NERVOUS SYSTEM. 



01 



body by the spinal cord and the nerves that originate there- 
from. It is egg-shaped, with the smaller portion toward the 
front, and the larger portion fitting closely to the rear and 
lower portion of the skull. It weighs somewhat more than 
three pounds, or about T ^ of the entire body. 2 It is delicate, 
and sensitive to pressure, blows, and jars ; hence it is securely 




Fig- 5i- 

Thh Brain Seen From Below.— 1. Great fissure. 2. Anterior lobes of cerebrum. 3. Posterior lobes 
of cerebrum. 4. Lobes of cerebellum. 5. Cranial nerves. 6. Auditory nerve. 7. Optic nerve. 8. 
Olfactory nerve. 9. Main body of medulla oblongata. 10. End of medulla oblongata. 



protected by the strong, bony case in which it is lodged. 
Besides its bony box, it is covered with membranes, and 
surrounded by fluids for still further protection. The mem- 
branes that cover the brain are three : (i) A tough, dense 
membrane, which lines the walls of the skull; (2) a delicate 
membrane, packed about the brain; (3) a soft, fine mem- 
brane, that lies next to the brain substance, and supplies 



I0 2 PHYSIOLOGY. 

the brain with blood. The brain, although ^ the weight 
of the body, requires i of the blood for its support. 

The brain is separated, with the exception of a connect- 
ing portion at the base, into right and left hemispheres. 
This division is made by a deep fissure, extending through 
the middle, from front to rear. See Fig. 50. This division 
makes two brains, that are partially independent of each 
other. 3 The brain is also deeply folded and wrinkled. 
These folds are called convolutions. The brain is formed 
of both kinds of nerve matter, so arranged that the gray 
covers the entire surface to the depth of J of an inch. 
The white matter is within, and connects all parts of the 
brain with the spinal cord at the base. The brain has three 
distinct parts: (1) Cerebrum; (2) cerebellum; (3) medulla 
oblongata. See Fig. 51. 

116. The cerebrum is the brain proper. It forms about 
•| of the whole mass within the skull. It occupies the 
upper portion of the cavity of the skull, projecting forward 
over the eyes, and backward over the cerebellum. Its 
surface is deeply and irregularly folded, and, if spread out, 
would cover about five square feet. See Fig. 50. The 
cerebrum appears to be the part of the brain that enables 
us to think. The gray matter arranged upon its surface is 
the true source of nervous force. 4 The cerebrum presents 
many minor ganglia of gray matter at its base, and numerous 
arches and passages, the description of which can not be 
included in these brief lessons. 

117. The cerebellum, or little brain, is situated under 
the rear portion of the cerebrum. It is closely connected 
with both the cerebrum and the medulla oblongata at the 
base of the brain. It is about i the weight of the cere- 
brum. It is composed of both gray and white matter, 
arranged as in the cerebrum. Its folds are regular, and 
so arranged that when the mass is cut the section shows a 
curious leaf-like figure. This figure is called the arbor vitas, 



THE NERVOUS SYSTEM. 



103 




from its resemblance to the leaf of a tree by that name. 
The cerebellum appears to be designed to control the 
muscular movements. 4 

118. The medulla oblongata is that 
portion of the brain by which all the other 
portions are united into one mass, and the 
whole connected with the spinal cord. It 
forms the passage-way to and from the brain. 
It is the most exquisitely sensitive portion 
of the nervous system. From it arise several 
of the nerves of special sense, and some 
other nerves of peculiar importance. One 
of the nerves from the medulla oblongata 
passes out to the stomach and lungs. This 
nerve controls the process of breathing. The 
least injury to the medulla oblongata at the 
origin of this nerve causes instant death. 4 

119. The spinal cord is a continuation 
of the medulla oblongata into the opening 
provided for it in the spinal column. It is 
protected by the vertebrae and a continuation 
of the membranes that cover the brain. It 
is about fifteen inches long, and as large 
around at the upper end as the little finger. 
The substance of the cord is chiefly white 
matter, with some gray matter extending 
through the middle portion. Deep fissures, 
extending lengthwise of the cord, separate it 
into right and left halves. The cord connects 
the brain and the nerves of the body. In 
Fig. 52, we see a front view of the left side 
of the spinal cord, showing the origin of the Fi s- 52. 
spinal nerves; 1 is a portion of the medulla Spinal CoRD - 
oblongata, 2 is the anterior fissure, 3 is the root of the 
eighteenth spinal nerve of the right side. 



104 



PHYSIOLOGY. 




120. Spinal Nerves. — From the sides of the spinal 
cord, as a trunk, there originate thirty-one pairs of nerves, 
called spinal nerves. See Fig. 52. These nerves originate 
upon opposite sides of the cord, in nearly regular intervals 
along its entire course, and pass out through openings 
between the vertebrae at the sides of the column. Each 
nerve springs from the cord by two sets of fibers, called its 
roots, one set of which comes off from the front portion, 
and the other from the rear of the side of the cord. These 
two sets of fibers soon unite to form 
one nerve, which leads away to certain 
parts of the body. The fibers that come 
off from the rear of the cord are dis- 
tributed to the skin. These are the 
fibers by which we feel, hence they are 
called sensory fibers. The fibers that 
arise from the front portion of the cord 
lead to the muscles. These are the fibers 
by which we move the muscles, hence 
they are known as motor fibers. The 
substance of the nerves is white matter. Each fiber of the 
nerve extends in unbroken line from the center in the cord, 
or brain, at which it originates, to the point at which it is to 
serve to give feeling or to produce motion. 

This arrangement puts every part of the surface of the 
body in separate communication with the seat of feeling, 
and enables the mind to tell just where the body is touched. 
In like manner, the mind can move any particular muscle. 
The sensory fibers end in minute loops in the papillae of 
the skin. The motor fibers end in the delicate covers 
of the muscular cells. By these two kinds of nerve fibers, 
the various portions of the body are connected with the 
brain, and the whole organism is enabled to feel and to 
move. See Fig. 53. For the general distribution of the 
nerves, see Plate IV. 



Portion of Spinal Cord — 
1. Body of cord. _'. A spinal 
nerve from left Bide of cord. 

3. Anterior roots of a nerve. 

4. Posterior roots. 



THE NER VO US S YSTEM. 1 05 



Notes. 

1. Arrangement of Nervous System. — The construction of the 
nervous system, and its manner of action, may be compared to the 
arrangement of a common electric battery used in telegraphy. The 
gray matter in the form of centers is like the battery cups in which, 
by chemical action, the electricity is generated, while the white fibers, 
that connect these centers and communicate with the skin and mus- 
cles, are like the telegraph wires, by which the messages are sent. 
The brain itself is like some central office, connected with a vast 
number of smaller offices and stations. At this center, news is con- 
stantly received from all directions, and, from this center, commands 
are sent out. The stimulus that is sent over the nerve fibers is like 
electricity, in many respects, and, by many students of physiology, it 
is thought to be electrical in character. 

2. Brain Weight. — The human brain ordinarily weighs about 
fifty ounces, and is generally large in proportion to the highness of 
intellectual power in the individual, though this is by no means a 
necessary relation, for many persons of eminent mental superiority 
have had quite small brains, while a few very large-brained persons 
have been notoriously indifferent in mental power. Evidently much 
more depends upon the quantity of gray matter, quality of substance, 
and fineness of development, than upon mass. Among the results of 
examination of the brains of distinguised men, the following weights 
are given : 

Cuvier 64.5 oz. Abercrombie 63 oz. 

Napoleon 53. " Schiller 63 " 

Daniel Webster 53.5 " Lord Campbell 53.5 " 

Agassiz 53.4 " De Morgan 52.7 " 

3. The Hemispheres of the Brain. — Either of the hemispheres 
of the brain may be very seriously injured, yet the person live, and 
finally recover. Some years ago, in Indianapolis, a man fell from the 
top of a load of hay, and, by striking upon the prong of a pitchfork, 
the prong ran directly through one hemisphere of the brain, from 
front to back. The prong broke off, and remained for several hours 
through the brain. It was finally removed, and the person recovered, 
without serious injury to the nervous system or the mind. During 
the war of the rebellion, there were many cases of recovery from 
gunshot wounds, in which the bullet passed completely through one 



106 PHYSIOLOGY. 

hemisphere of the brain. A remarkable case of injury is upon record 
in which, in blasting with gunpowder, a pointed iron bar, three and 
a half feet long and one inch and a quarter in diameter, was driven 
completely through the side of the head of a man. It entered the 
skull below the temple, and made its exit at the top of the forehead. 
The man lay in a delirious, semi-stupefied state for about three 
weeks. At the end of sixteen months he was in perfect health, with 
the wounds healed and the mental and bodily functions unimpaired, 
except that the sight was lost in the eye of the injured side. 

4. The Divisions of the Brain. — If the cerebrum is removed, 
as has frequently been done with birds and other brute animals, the 
animal may continue to live. It can stand or walk, it breathes, and 
digests its food, but loses all power of judgment — seemingly, it loses 
all mental activity. If the cerebellum is removed, and the remainder 
of the brain left uninjured, the animal appears to retain its mental 
faculties, continues its vital processes, but loses all control over its 
voluntary muscles. The medulla oblongata is too sensitive, and too 
intimately connected with the processes of breathing and circulation 
to admit of mutilation without causing death. The spinal cord may 
be cut, by which injury all communication is destroyed with the 
part of the body below the point of division. From these rude 
experiments, and from some other data, it is thought that the cere- 
brum is the part chiefly engaged in mental activity; the cerebellum, 
in controlling voluntary muscular motion ; the medulla oblongata, 
in presiding over the vital processes; the spinal cord, in connecting 
the brain and body. 



Suggestive Questions. 

What are the uses of the nervous system? What are the uses 
of the cerebro-spinal nervous system ? What are the uses of the 
sympathetic nervous system ? What are the uses of the brain ? 
What are the uses of the different parts of the brain? What are 
the uses of the spinal cord? What are the uses of the nerves? 
How do the gray and white matter differ? How does the human 
brain differ from the brains of brutes? How do we feel? How 
do we move ? 



CHAPTER XII. 



THE NERVOUS SYSTEM. (Concluded) 



121. The sympathetic nervous system consists of 
a double chain of small 
nerve centers, located with 
one chain on each side of 
the spinal column. This 
chain extends the entire 
length of the trunk. There 
are many other centers lo- 
cated elsewhere. From these 
centers arise numerous nerve 
fibers, that connect the cen- 
ters with one another, and 
with the various vital organs. 
Some of the fibers of the sym- 
pathetic system connect with 
the spinal cord and brain. 
By this general union, all the 
parts of the body are bound 
together as one organism. 
One of the members can not 
suffer injury or distress with- 
out causing all the others, 
even the brain itself, to 




Fig- 54- 

Diagram to Indicate the Arrangement op 
the Sympathetic Nervous Centers and Fibers. 



(I07) 



108 PHYSIOLOGY. 

suffer also. Thus the stomach can not be deranged without 
distress to all the body. Pain can not exist in the heart 
without alarm to the whole body. One eye can not suffer 
without involving the other. It is because of this sym- 
pathetic union, established by this system, that it is called 
the sympathetic system. The numerous small centers of 
this system act somewhat as so many little brains, which 
control the action of the vital organs quite independently 
of the brain proper. The heart of a turtle will beat for 
a time after being cut out of the animal, because it has 
so many nerve centers in it that act to give it motion. 
See Fig. 54. 

122. The Function of Nervous Tissue. — The fibers 
that have their outer ends in the skin are sensitive to touch 
and to changes in temperature. They convey the irritation 
they receive to the centers at their inner ends. In this way 
they cause an impression to be made on the centers. The 
impression made on the centers, especially on the brain, 
causes the mind to feel. 1 The impression made on the 
center may be so customary that the mind takes no notice 
of it. 

The centers send out a nervous impulse along the fibers 
that lead to the muscles. These impulses sent to the mus- 
cles cause motion. If your hand touches a hot object, the 
ends of the nerves are irritated by the burn. This irritation 
is quickly conveyed to the brain. An impulse is sent to the 
muscles of your arm to move the hand away. The passage 
of irritation along the fibers is very rapid, so that the time 
is very short between the touching of the hot object and the 
taking of the hand away. 

If the sensory fibers connecting any part with the brain 
are cut or seriously injured, there is loss of feeling in the 
part. If the motor fibers connecting any muscle with 
the brain are cut or injured, all power of motion in the 
muscle is lost. If both kinds of fibers are destroyed, both 



THE XERVOUS SYSTEM. 109 

feeling and motion are lost. These different conditions 
produce the various kinds of paralysis. 2 

123. Reflex Action. — The nerve centers may perform 
their action of sending out motor impulses without the con- 
scious action of the mind. If the irritation is extreme, the 
centers act before the mind has time to consider and direct 
the movement. In the case in which your hand touches the 
hot object, you take the hand away instantly, before the 
mind has time to act. If any person sticks you with a pin, 
you flinch instantly. If you are about to fall, you instantly 
catch your balance. This action of the nervous system, in 
which the mind does not seem to act, is called reflex action. 

If the spinal cord is cut so as to destroy all connection 
with the brain, the nerves connected with the gray matter 
of the cord will still perform reflex action. If the part of 
the body supplied by these nerves be burned or pinched, the 
part thus injured will be thrown into violent motion. In 
this case, the mind can not receive any feeling from the 
injured portion, and is wholly unconscious that the motion 
is produced. This is positive proof that the centers may 
give impulses that cause motion without the action of the 
brain. Such action is purely reflex. 

The uses of reflex action are of the most important char- 
acter: (1) It relieves the mind; (2) during sleep it continues 
the vital processes; (3) during the day it performs the usual 
acts of standing, walking, and working; (4) it conducts the 
operations of the sympathetic system; (5) it enables the 
mind to perform its usual acts with ease. 

Reflex action not only directs the processes of the body, 
but largely invades the realm of intellectual and moral 
action. The whole matter of habit, whether of body or 
mind, is a manifestation of reflex action. As the nervous 
system acts once under certain conditions, so it is disposed 
to act again under similar conditions. By repetition, the 
action follows without thought. 



no 



PHYSIOLOGY. 



124. Hygiene of the Nervous System. — Because all 
the other organs depend upon the nervous system for their 
control and energy, and because the mind, too, depends 
upon the activity of the nervous system, the health and 
vigor of the nervous system itself become a matter of great 
importance. 

The nervous system may be naturally strong, or weak, be- 
cause of the conditions of parents. Any kind of nervous 
disease in parents tends to produce corresponding feebleness 
in their children. This tendency is notably true of insanity, 
epilepsy, intemperance, licentiousness, and mania of all 
kinds. 

Great waste of tissue and energy attends all nervous 
action. The nervous system, like all other parts, is depend- 
ent upon the blood for repair. Hence, it follows that faulty 
nutrition and impurity of blood result in nervous weakness. 
Impure air, by its effects on the blood, deadens the energies 
of the nervous system. Faulty excretion, by retaining the 
impurities in the body, acts similarly. The nervous system 
suffers through imperfect respiration, insufficient diet, and 
imperfect digestion. Many substances, which are often 
taken as food, drink, or medicine, affect the nerves by ex- 
citing or paralyzing them. Such is true of tea, coffee, 
tobacco, opium, alcohol, chloroform, and other articles of 
the same kinds. 

Like all other organs, the nervous system requires proper 
exercise for its growth and continued vigor. The brain 
requires for its best development that the individual shall 
have proper physical exercise, so that the body may be 
strong. The brain, as the organ of the mind, requires 
proper mental exercise. The idle mind becomes weak. The 
nervous system and the mind are so closely related, that 
whatever affects one also affects the other. When the 
system is healthful and vigorous, mental action is most 
forcible and reliable. 6 Whatever weakens the nervous sys- 



7 HE NER VO US S YSTEM. 1 1 1 

tern, or disturbs it, produces corresponding disturbances in 
the mind. What is known as insanity, in which case the 
judgment and reason are dethroned, is the result of nervous 
weakness, disease, or inflammation. Insanity may arise 
from lack of nourishment, prolonged exhaustion by disease, 
great fright, excessive grief, very great excitement, over- 
work, financial embarrassment, and other great strains on 
the nervous system. Insanity occurs most often as the 
result of heredity. In such cases, children inherit nervous 
weakness from their parents. 

The nervous system needs proper rest. All other parts 
of the system are arranged with intervals of rest, alternating 
with action, during day and night. The cerebrum can not 
rest while awake, but requires a prolonged season of deep 
sleep. During sleep, the brain repairs itself. Without 
sleep, it becomes exhausted. If a person loses the sleep 
of one night, the brain is weak and restless, until the loss 
is repaired. Partial rest to the brain may be found in change 
from one kind of mental work to another. Recreation and 
amusement may relieve mental strain. 

125. The Effects of Alcohol and Other Stimulants 
and Narcotics on the Nervous System. — Alcohol, 
when taken into the alimentary canal, is readily absorbed by 
the blood. The circulation of the blood quickly distributes 
the alcohol throughout the system, and brings it in contact 
with all the nerves of the body. The alcohol is attracted to 
nervous matter because of the large amount of water con- 
tained in the nerves and centers, for alcohol and water have 
great attraction for each other. The alcohol hardens the 
extremities of the nerves, and makes them less sensitive. 
The person loses the power to feel as acutely as he did be- 
fore. We call this loss of feeling paralysis. The alcohol 
also inflames the nerve centers. For a short time after 
taking alcohol, the person seems stronger, the mind is 
brighter, the heart beats faster, the circulation of blood is 



H2 PHYSIOLOGY. 

quickened, and the muscles are excited to action. This 
increase in the action of the system is called stimulation. 
Stimulation is followed by a season of corresponding de- 
pression, in which there is dullness, weakness, stupidity, 
and lowness of temperature. The effects of the alcohol on 
the nervous system are paralysis, irritation, and inflammation. 
If the quantity of alcohol taken be great enough, or if the 
effects are often repeated, nervous force becomes deadened, 
so that the person becomes unable to walk or to think. 
These depressing effects tend to cause death. It is because 
of these effects of alcohol on the nervous system that all 
medical writers call alcohol a narcotic poison. 

The effects of alcohol on the mind are as follows : (i) For 
a short time it produces a pleasing feeling, in which the per- 
son seems bright and strong in mind, and the person is partly 
relieved from bodily pain ; (2) following the first effects, the 
mind grows restless, is depressed, and suffers a craving for 
more stimulation. By the action of the alcohol on the 
system, the mind loses its power to perceive correctly, and 
to judge rightly. A person under the influence of alcohol 
is rash, careless, irritable, and dangerous. The influence is 
often such as to cause a complete change in the character 
of the person. Sometimes persons who, when free from it, 
are kind and gentle, become cruel and desperate; the re- 
fined and delicate grow coarse and vulgar. 

The most serious injury that alcohol produces to the mind 
is that it tends to destroy the power of the will. Just as 
the person can not think so correctly, and can not feel so 
fully, so his power to control himself is weakened. No 
person can be more hopelessly wanting in self-control than 
an intoxicated person. Along with the weakened will, there 
is produced a craving for more stimulant. The person who 
uses alcohol is in danger of being led to use it to excess, and 
to form an uncontrollable narcotic appetite. 

Added to the dangers and injuries to the person who uses 




Plate IV. 



NERVES. 



THE XERVOUS SYSTEM. 



"3 



the alcohol, there is also danger of transmitting nervous 
weakness and narcotic appetite from parents to children. 
The children of parents who use alcohol and other stimulants 
generally suffer some kind of nervous weakness therefrom. 

Intoxication is temporary insanity. It is not surprising 
that many repetitions of intoxication frequently lead to 
permanent forms of insanity. The use of alcohol is one 
of the chief causes of insanity. 

Tobacco, like alcohol, is a poison. When chewed or 
smoked, its poisonous portion is absorbed by the blood and 
circulated through the system. Its effects are most fully 
shown in injury to the blood itself, and in paralysis of ner- 
vous force. Its influence on the nervous and muscular 
systems is so powerful that its use in medicine is regarded 
as too dangerous for general practice. Its use causes 
diseased conditions of the vital organs. The stomach, the 
liver, the heart, and the nervous centers suffer most from 
its use. The effects of tobacco blunt and degrade the 
mind. By its narcotic effects, its use fixes upon the system 
the most slavish conditions of the will. The person who 
permits himself to become addicted to its habitual use loses 
his power to stop the evil habit. No intelligent person, 
who uses it, will advise another to begin the use of it. 

Tea and coffee affect the nervous system by causing 
stimulation. In their excessive use is to be found the 
cause of much headache, dispepsia, craving, and irritability 
of temper. 

Opium is a gum made from the juice of the poppy. It 
may be smoked and chewed like tobacco. It is much used 
as a medicine, in the form of morphine. It allays pain, and 
produces deep sleep. If a sufficient quantity of the drug is 
taken, the sleep which it produces ends in death. These 
effects are caused by its powerful narcotic properties, Like 
alcohol and tobacco, it is a narcotic poison. Its use tends to 

produce an uncontrollable appetite. Persons who once form 

Pgy.— 8. 



ii4 



PHYSIOLOGY. 



the habit of using it, rarely ever escape from the craving 
that binds them to continue its use. Its habitual use causes 
the organs of the body to become diseased, and weakens 
and degrades the mind in an alarming manner. 

Chloral hydrate and chloroform are drugs that are much 
used to relieve pain and to produce sleep. Their use is 
attended with the same dangers that apply to other nar- 
cotics. 

The sleep produced by narcotics is not natural. While 
such sleep gives rest, it does not restore the body and mind 
as natural sleep does. Sleep caused by drugs is frequently 
followed by sick-headache and lassitude. The habitual use 
of sleep-producing drugs is a practice that tends to the most 
fatal results. 



Notes. 



i. Sensibility of Brain Substance. — The brain itself is insensible 
to touch, for when the skull is broken or cut away the brain thus 
exposed may be cut or torn without producing the least pain. 
Situated as it is within the dense skull, it is unprovided with 
sensory fibers. The substance of the brain is readily paralyzed by 
pressure; if the skull were fractured, so that a portion of the bone 
pressed upon the brain, the individual would lie in an unconscious 
state until such pressure was removed, and unless relieved would 
speedily die. 

2. Paralysis. — From various experiments, it appears that the fibers 
that connect the brain with the body cross over from the left side 
of the brain to be distributed to the right side - of the body, and 
from the right hemisphere of the brain to the left side of the body. 
By this arrangement an injury to the left brain, producing paralysis, 
will affect the opposite side of the body. The fibers of the cranial 
nerves do not cross over, so that an injury to one hemisphere of 
the brain may paralyze the eye and muscles of the face upon the 
same side with the hemisphere, and the nerves of the opposite 
side of the trunk and its extremities. 



/ HE A T ER VO US S YS 7 EM. 



"5 



Suggestive Questions. 

What is paralysis? Under what condition of the nervous system 
may we lose feeling from a part, but retain the power to move it? 
How may a part of our body move without our being conscious of 
its movement? What is sleep? What is pain? In what ways is 
pain useful? In cutting off an extremity, what parts, when cut, will 
give greatest pain? How does the shape of the head indicate 
character? How do narcotics affect the nervous system? How 
do impure air and indigestion affect the nervous system? What 
are the objections to the use of tobacco? What is the character 
of opium, hydrate of chloral, and chloroform? 



Topical Outline. 



Nervous System. 



1. Character of nervous tissue. 

a. General structure. 

b. Kinds. 

(1) White, or fibrous. 

(2) Gray, or cellular. 

c. Function of each kind. 

2. Divisions. 

a. General. 

b. Special. 

3. General nervous system. 

a. Cerebro-spinal. 

(1) Purpose. 

(2) Parts. 

(a) Brain. 

(b) Spinal cord. 

(c) Spinal nerves. 

b. Sympathetic. 

(1) Purpose. 

(2) Parts. 

(a) Ganglia. 

(b) Nerves. 



4. Function of tissues. 

a. Purposes of brain. 

(1) Cerebrum. 

(2) Cerebellum. 

(3) Medulla oblongata. 

b. Purposes of nerve fibers. 

5. Reflex action. 

6. Hygiene. 

a. Need of nourishment. 

b. Need of exercise. 

c. Effects of over-excitement. 

d. Need of rest. 

e. Effects of. narcotics. 

(1) Alcohol. 

(2) Tobacco. 



CHAPTER XIII. 

SPECIAL SENSES. 

126. General and Special Sensibility. — The mind 
learns to locate the feeling in the exact part of the body 
at which the ends of the nerves are touched. The feeling 
is really produced in the brain, and it is the mind that 
feels, but the mind locates the feeling at the outer ends 
of the nerves. For instance, if the right hand is burned, 
the feeling is referred to the hand and to the exact por- 
tion that is injured. For this reason, we say the hand 
feels. 

The acuteness of feeling in any part depends on several 
causes: (1) The highly sensitive parts have a greater num- 
ber of nerves extending to them ; (2) the ends of the nerves 
in these sensitive parts are exposed so as to more fully 
receive the effects of the irritation; (3) the continued use 
that the mind makes of certain parts in feeling develops 
their sensitiveness. 1 

127. Pain. — When, from any cause, the nerves are very 
greatly excited, or are injured in their structure, the result 
is pain. Pain results, too, from the excessive use of any 
organ. Pain limits us in the use of our powers. Pain 
usually attends disease, and indicates what parts are suffer- 
ing. Hence pain, though a present evil and greatly dreaded, 
protects us from danger, prevents us from using our bodies 

(116) 



TOUCH. 



117 



too much, and warns us of the approach and presence of 
disease. 

128. Special Sensation. — Some parts of the body are 
designed to give feelings from one cause, and other parts 
from other causes. The fingers touch, the tongue tastes, 
the eye sees, and the ear hears. All of these results are 
different feelings, coming from certain parts of the body. 
The mind learns by experience what these different kinds 
of feelings are, and learns also to tell something of the 
various causes that produce the feelings. In this way the 
mind gains different kinds of knowledge. These special 
adaptations of the nervous system to receive various kinds 
of feeling, are called the special senses. The special senses 
seem designed to give the mind its varied knowledge of 
the world. They are the windows of the mind, through 
which we look out, and gain knowledge of the things about 
us. 

I2g. The special senses are feeling, tasting, smelling, 
seeing, hearing. The organs of special sense are. respec- 
tively, the skin, the mouth, the nose, the eyes, the ears. 
While each of these is very sensitive to the peculiar irrita- 
tion which it receives, it is wholly insensible to the causes 
that excite the others. For instance, the eye may perceive 
the most delicate shade of light, but can in no way see the 
loudest sound; and the tongue, though able to detect the 
most delicate flavor, can neither hear nor see. 

Each special organ of sense is supplied with special 
nerves; i. e., nerves that are not used for any other purpose 
than for the peculiar feeling of that organ. These nerves 
lead to special nervous centers. 

130. Touch. — The true skin, covering the entire body, is 
the organ of touch, because it gives the mind knowledge of 
the contact of things that touch it. The skin also feels the 
temperature of things. The hands are the special organs 
of touch. The hands are used to feel objects, and, from 



u8 PHYSIOLOGY. 

the effects produced, the mind learns whether the surface 
be smooth or rough, warm or cold, hard or soft, and the 
like. By grasping the object, the hand fits about it, so that 
the mind learns the size and shape of objects held in the 
hand. By reaching out the hands and arms, the distances 
of bodies that are within reach is learned. It is by prac- 
ticing the eye, in association with the hands, that the mind 




Fig. 55- 
The Nerves of the Finger. 

learns to judge of size, form, and distance.' 2 Fig. 55 rep- 
resents the nerves of the finger. 

By its structure, the hand is adapted to be used as the 
organ of grasp and touch, and to serve the mind in many 
other ways, such as in writing, drawing, painting, sculpture, 
in performing on musical instruments, and in working at 
skillful trades. The hand is very flexible, so as to adapt 
itself to almost any shape. Its many joints, muscles, and 
tendons give it the greatest variety of motions. Its move- 
ments are easy, light, and rapid. Its location at the end 
of the arm permits it to touch any portion of the body. 
The two hands, acting together, perform thousands of the 
most intricate acts, and serve the mind and body in an 
untold number of ways. 

131. The Nerves of Touch. — Any portion of the skin 
that possesses the sense of touch, consists of three parts: 
(1) A deep layer of fibrous tissue, (2) a delicate network 
of nerves running through the deeper layer, and (3) an 
outer, insensible layer, to shield the sensitive parts from 



TASTE. 



119 



injury. Wherever the sense of touch is very delicate, as 
it is in the palms of the hands, and on the fingers, the 
deeper layer is raised into great numbers of closely-set 
points, about one hundredth of an inch in length, called 
papillce. These papillae project from the lower layer, 
and the insensible layer fills in between them, and covers 
their ends. The outer ends of the sensory nerves are in 
these papillae. The papillae are most numerous in the more 
sensitive portions; it is estimated that there are 20,000 
of them to the square inch in the palms of the hands. 

The acuteness of the sense of touch may be greatly in- 
creased by cultivation. This is true of all the special senses. 
By fixing the attention upon the feelings produced, the mind 
learns to understand more readily the sensations made on the 
brain, and to perceive differences that would not otherwise 
be noticed. The wonderful degree to which the education 
of the touch may be extended is well shown in the powers 
which the blind gain in learning to read freely from raised 
letters. These blind readers pass the tips of the fingers 
over raised print. By touching the words in this way, they 
recognize them as the ordinary reader does by seeing the 
word. To master a new word, they feel the letters, and 
spell it in that way. These blind persons also learn to per- 
form skillfully on musical instruments, to do fine sewing, 
and to make many articles, requiring rare skill. They 
perform these difficult tasks by the education of their sense 
of touch. 

132. Taste. — The various substances that are taken into 
the hand produce quite the same impression on the nerves 
of touch. If these substances be placed in the mouth, they- 
affect very differently the sensory nerves of the mucous 
membrane covering the lips, cheeks, and tongue. They 
touch the parts of the mouth as they do the hand, and pro- 
duce feelings of smoothness, softness, warmth, and the like, 
as they do in the hand. In addition to these feelings, some 



120 PHYSIOLOGY. 

of the nerves supplied to the mouth receive peculiar feelings 
from the objects that touch them. By these peculiar feel- 
ings, the mind learns the taste of any thing, whether it is 
sour or sweet, salty or bitter. In order that substances may 
be tasted, they must be moistened and dissolved, so as to 
come in contact with the nerves of taste. It is not all 
articles that produce taste, nor are all portions of the 
mouth supplied with these peculiar nerves. The parts 
that are most sensitive to taste are the outer end of the 
tongue, its border near the teeth, and the surface of the 
back portion. 

133. The tongue is the organ of taste. The nerves 
supplied to it for tasting come from particular points on the 
medulla oblongata, and have their ends exposed on the 
surface of the tongue in a peculiar manner. The tongue is 
covered with great numbers of papillae, which give to it a 
velvety appearance. In some parts, the tongue is covered 
with ridges. Toward the back portion, the tongue is sup- 
plied with numerous glands and sack-like depressions, which 
pour out their juices to dissolve the substances, and thus aid 
the nerves in tasting. The nerves of taste end in the papillae 
of the tongue and about these glands. The border of the 
tongue seems most easily affected by sweets and sours; the 
back portion is most affected by salts and bitters. The 
impression made on the nerves of taste lasts for a brief 
season, so that a strong taste can not be immediately re- 
moved from the mouth. 

By the habitual use of substances that have strong or 
pungent taste, we lose the ability to detect delicate flavors. 
The use of narcotics, such as tobacco and alcohol, deadens 
the sensitiveness of the nerves of taste. Very great delicacy 
of taste may be acquired by cultivation. Taste seems de- 
signed to guide us in the choice of food, and to lead to 
proper mastication. Brute animals, whose tastes are per- 
fectly natural, are seldom misled in selecting food. 



■ 



SMELL. 121 

134. Smell. — The gases and vapors that pass into the 
nose with the breath come in contact with extremely delicate 
nerves. These nerve fibers end in the moist, mucous mem- 
brane that lines the upper portion of the nose. The sub- 
stances that strike against these nerves produce peculiar 
effects, which the mind learns to know as odor, or smell. 
The nose is the special organ of smell. Every one is familiar 
with the fragrance of flowers, the savory odor of cooking 
meats, and the disgusting stench of decaying matter. These 
feelings, which we call smell, are probably produced by 
particles of substances that are floating in the air. These 
particles, upon being breathed into the nose, touch the 
nerves of smell. These nerves are called the olfactory 
nerves. 

Smell seems designed to co-operate with taste in deciding 
our choice of food and drink. Smell seems particularly 
designed to detect impurities in the air. Smell is a more 
delicate sense than taste or touch. In some brute animals, 
this sense is astonishingly acute. The deer can smell the 
hunter many rods away. The hound follows the trail of a 
hare by the smell arising from the pressure of the hare's feet 
on the ground and grass. The hound may also follow his 
master's footsteps through the crowded street, hours after he 
has passed along, by the odor arising from the pressure of 
the master's feet on the pavement. 

Evidently taste and smell are far more special in their 
nature than is touch, although they all depend on the con- 
tact of objects with certain nerves. 



Notes. 

1. Sensitiveness. — The relative number of nerves in the different 
parts of the body may be measured by using a pair of dividers as 
follows : Place the two points of the dividers near together, and touch 
them to the tips of the fingers. We can detect the two points, even 



122 PHYSIOLOGY. 

if they are brought almost together. Now place the points against 
the back, and we shall find that we feel but one point. The two 
points may be separated an inch or more, and yet we can feel but 
one point in touching them to some parts of the back. This is 
because there are so few nerves on the back. Upon the cheeks, 
lips, fingers, or tongue, we can feel the two points, even if they 
are brought to within less than the twentieth of an inch. This 
is because the nerves are so much more numerous in these more 
sensitive portions. 

2. Judgment of Form and Distance. — Without ever touching a 
round body, we can not judge of its form by the eye. A sphere has 
the same outline as the flat circle. Glass and water have the same 
appearance, and, to one who had never touched them, they would 
appear equally hard. To a young child, the moon is as near as 
the window, or as the chair. It is only by extending the arms and 
measuring distances that the mind finally learns to judge of dis- 
tance through the eye. 



Suggestive Questions. 

Why does a tiny object appear to be so large when lodged in the 
eye? How does special sensation differ from general sensibility? 
How do we locate the exact spot upon the skin that is touched 
by any object? What knowledge do we gain through the agency 
of the hand? In what ways is the hand adapted for its uses? 
When the cuticle is removed, why does the skin beneath smart? 
Why does the warmth of the fire feel greater to the palm than 
to the back of the hand? Why may the special senses be so 
improved by practice? 

How do the blind read? How does taste differ from touch? 
How does taste aid in protecting us ? What protection does smell 
afford? How does the use of tobacco and alcohol affect the nerves 
of taste? 



warn 



CHAPTER XIV. 

SPECIAL SENSES. (Continued) 

135. Sight. — Light comes into our eyes from the things 
about us, and we see these objects. The light from a candle 
produces an effect on the nerves of the eyes, so that we 
see the candle. So the light reflected from the book 
causes us to see the book. This sense is called sight. By 
this sense, we learn to judge of the form, size, color, and 
distance of objects. 

136. The eyes are the special organs of sight. There 
are two eyes. They usually act together, so that, in seeing 
anything, we use them both on the same object. We may 
see by using one eye alone. Persons who lose the use of 
one eye, learn to see with the remaining eye quite as well 
as others do with both. The eyes are placed very near the 
brain, in the deep sockets just under the front part of the 
cerebrum. By this position, the eyes are high, so that the 
person may see far, and, by the free movements of the head, 
the eyes may be turned quickly to see in any direction. 

137. The protecting parts of the eyes are designed to 
prevent injury to these delicate organs. The bony orbits 
project around the eye, so that objects can not readily strike 
the ball. The brows and lashes shade the eyes from too 
much light, and prevent dust and sweat from entering the 
eyes. The lids close over the balls to shut out all light while 

(123) 



124 PHYSIOLOGY. 

we are asleep, and, while we are awake, they keep the 
eye clean. The lining of the lids is a very sensitive mem- 
brane. If anything enters the eye, it gives pain to this 
membrane, so that the person has no rest until the object 
is removed. 

138. The Tears. — The lachrymal glands are located 
in the eye sockets, just back of the outer end of the eye- 
brows. These glands secrete the tears from the blood 
and pour them upon the balls. The tears are constantly 
flowing into the eyes. They flow across from the outer 
upper corner to the lower inner corner, and pass into the 
nose through tiny ducts, opening into the nose for that pur- 
pose, called lachrymal ducts. The tears keep the eyes 
moist, and wash away the dust, so that the eyes are clear. 

If anything gets into the eye to cause irritation, the tears 
flow in rapidly to aid in removing the object. In crying, 
the tears flow in faster than they can flow into the nose, so 
that they run over the edges of the lids. There are many 
little glands along the edges of the lids, that secrete an oily 
substance on the edge, to prevent the lids from sticking 
together, and to prevent the tears from flowing over. 

The eye-balls do not fill the sockets, but are packed about 
by fatty matter, which forms a cushion for the eyes to rest 
on, and upon which to move freely. 

The eyes are moved by muscles attached to the balls, and 
fastened to the back part of the socket. There are three 
pairs of muscles to each ball. 

139. The Eye-balls. — By pressing the balls between 
the thumb and fingers, we find they are quite firm and 
hard. By taking the eye-ball of an ox to pieces, we shall 
find that it is filled with jelly-like fluids, surrounded by an 
outer shell or wall. The wall of the eye is formed of three 
layers or coats. 1 See Fig. 56. 

The outer coat of the eye-ball is thick and tough. It is 
called the sclerotic coat. It forms the white of the eye. 



SIGHT. 



125 



This coat covers the front portion with a clear coat, called 
the cornea, designed to admit the light. This outer coat is 
designed to preserve the shape of the eye and to give it 
strength. The second or middle coat is the choroid coat. 
This lines the interior of the eye with a dense black pigment. 
In front, this second coat forms the iris, which gives color to 
the eye. Through the iris there is a round opening, called 
the pupil, to permit the light to enter the eye. The opening 
changes in size, growing smaller, so as to shut out some of 
the light when the 
light is too strong, 
and becoming larger 
as the light grows 
weaker. The inner 
or third coat is the 
retina. This is a 
thin membrane, cov- 
ering the interior of 
the eye, and having 
the nerves of sight 
distributed through 
it. 

The jelly-like fluids 
that fill the eye are called humors. There are three humors : 
(1) The aqueous, which fills a small portion of the eye in 
front; (2) the crystalline, which is in the shape of a lens, 
about as large as a medium-sized button, just back of the 
aqueous humor; (3) the vitreous, which fills the main 
portion of the eye-ball. See Fig. 56. 

The eye is supplied with special nerves of sight, called the 
optic nerves. These nerves enter the eye at the back 
portion of the ball, and spread out on the inner surface 
of the walls of the eye. These nerves cover only the back 
portion of the interior, where the light that enters the 
pupil falls. 




Fig. 56. 

Section of the Eye.— 1. Optic nerve. 2. Retina. 3. Vit- 



reous humor, i. Crystalline lens 
Cornea. 7. Iris. 8. Pupil. 



5. Aqueous humor. 



126 



PHYSIOLOGY. 



140. How We See. — We do not touch the thing we 
see, as we do the objects we taste. Instead of having the 
objects come into our eyes to touch the nerves of sight, the 
nerves of the eye are so delicate that they are affected by 
the light that comes from the object into the eye through 
the pupil. 

Light is a kind of wave-like motion, and, in coming 
against the delicate nerves, irritates them. The light passes 
off in all directions from objects in diverging straight lines. 
Some of these lines of light pass in through the pupil. In 
passing through the crystalline lens, they are so turned from 




Fig- 57- 
Diagram op the Eye. — 1. Lines ofli^ht from end of arrow. 2. Small, inverted image in the eve. 



their course that all the rays or lines that come into the eye 
from any point on an object are brought together at one 
point on the retina, and all the lines from any other point 
of the object we see, are brought together at another point 
on the retina. It is in this way that there is a complete 
image of the object we see made on the retina. See Fig. 57. 
This image is very small, but is bright, and has the shape, 
shade and color of the object seen. From this image on 
the nervous membrane of the eye, the mind learns to judge 
of the shape, shade, and color of an object, just as it judges 
of an object by taste or smell. 

The image is so small that it seems wonderful that the 



SIGHT. 



127 



mind can use it so perfectly. It may be that the whole 
landscape, which covers many miles in extent, is pictured in 
an image on the back of the eye, so small that it would not 
cover more than the surface of the little finger-nail. The 
mind, however, can fix its attention on any point in this 
image, and see the same point in the landscape. From the 
point that is affected in the eye, the mind learns to judge 
of the direction of the light and of the direction of the 
object that is seen. By practice, we learn also to judge 
of the size and distance. 

The image in the eye is wrongside up, but the mind has 
learned by experience to judge of the object as erect. 

141. Near-sightedness. — The crystalline lens brings 
the rays of light together on the retina to form the image. 
If the lens is too nearly round, it brings the rays together 
before they reach the retina, so that no image is formed. 
Persons having such eyes are said to be near-sighted, be- 
cause they can only see objects that are very near the 
eyes. This defect of the eyes may be remedied by wearing 
concave glasses, to counteract the roundness of the crystalline 
lenses. 

142. Far-sightedness. — If the lenses are too nearly 
flat, the rays of light are not brought together upon the 
retina, so that no image is formed. Persons with such eyes 
can see only distant objects. They are said to be far-sighted. 
Many old persons are far-sighted. This defect of the eyes 
is relieved by wearing eye-glasses that are convex, so as to 
bring the rays of light together, to form an image on the 
retina. 

143. Hygiene of the Eyes. — The eyes may be injured 
by looking at objects that are very brilliant. To look 
directly at the sun is painful and injurious. By straining 
the eyes in trying to see in light that is too feeble, the 
eyes are injured. To read or sew by faint light injures 
the eyes. The light, in reading, or in other cases in 



i 2 8 PHYSIOLOGY. 

which the eyes are used continuously on the same object, 
should come upon the page, from the rear or side of the 
person. By this means, the direct light does not enter the 
eyes, but the light is first reflected from the object, and 
then enters the eye. 

The eyes may be injured by using them too intently, or 
too continuously, on very fine work of any kind. To pre- 
vent injury in this way, the eyes should be rested and 
relieved by being used in other ways. 

If, from any kind of use, the eyes become inflamed, the 
best relief is to give them perfect rest. Keep them closed, 
wear colored glasses for a time, or remain in closed or 
shaded rooms, if necessary. 

If an object gets into the eye and causes pain, remove it 
promptly, by lifting or turning the lid, and taking the folded 
corner of a soft handkerchief, or the rounded end of some 
smooth object. Do not rub the eye, nor wipe it excessively, 
for such practices will increase irritation. 

Keep the eyes clean by thorough washing in clear 
water. 



Note. 



i. Dissection of an Eye. — The structure of the eye may readily 
be seen by cutting open the eye of a beef or hog. Take the eye 
from the socket immediately after the animal is killed. With a pair 
of sharp scissors trim away all muscle and fat from the ball. The 
optic nerve may easily be seen at the back portion, very nearly 
opposite the pupil in front. Hold the ball firmly in one hand, and 
by careful pressure push the sharp point of the scissors through the 
back part of the eye. Having done this, cut forward to the margin 
of the cornea. Turn the eye, and cut in the opposite direction in 
like manner. The ball may now be turned " inside out." The 
vitreous humor may be removed into a dish, and the crystalline lens 
may be taken out. The coats may be examined, and all the parts 
exposed to view. Take the lens between the thumb and finger 
and use it as a magnifying glass. Hold the lens in front of the 



SIGHT. 



129 



window, about twenty feet away, and place a piece of paper half an 
inch behind the lens for a back-ground. In this way, you may 
obtain a small bright image of the window. These simple experi- 
ments illustrate the uses of the lens in the eye. 



Suggestive Questions. 

What is it that we feel in seeing any thing? Is there an image 
in each eye? If there is an image in each eye, why does not every 
object seem double? What advantages are gained by having the 
eyes placed where they are ? What are the eye-lashes for ? From 
where do the tears come? What are tears for? How may we 
examine the structure of the eye? The iris of the cat's eye is 
nearly closed in the day time, but is wide open at night; why is 
this so ? What is light ? If the image is wrongside up, why does 
not the object appear so ? Why do old people wear eye-glasses ? 
How are we liable to injure the eyes? If the eyes become weak, 
what is the best treatment for them? 



Pgy.-9. 



CHAPTER XV. 

SPECIAL SENSES. (Concluded) 

144. Hearing. — The ear is the special organ of hearing. 
There are two ears. They are less closely related than are 
the two eyes. For protection, the ears are located at the 
base of the skull. The internal portion of the ear, which 
is the most important part of it, is inclosed in a very hard 
part of the skull, called the petrous bone. 

The ear has three parts: (t) The outer, (2) the middle, 
(3) the inner. See Fig. 58. 

The outer ear includes: (1) The shell-like part that pro- 
jects from the side of the head; and (2) the canal, or air 
tube, leading into the middle ear. The shell-like part is 
called the concha. It is formed of thin cartilage, covered 
with skin. It catches the sound, and directs it toward the 
inner parts of the ear. The canal leading from the concha 
is an opening through the petrous bone, lined with skin. It 
is about one fourth of an inch in diameter, and an inch 
long. It is an air chamber, and conducts the sound toward 
the inner ear. The inner end of this canal is closed by a 
membrane, which is stretched tightly across it. This canal 
is called the external auditory canal. 

The middle portion of the ear is called the tympanum. 
It is an air chamber in the petrous bone, about as large as 
a small cherry. Its outer wall is formed by the thin mem- 
(13°) 



wmm 



HEARING. 



J 3i 



brane across the end of the external canal. This is called 
the external membrane of the tympanum. Sometimes it is 
called the outer drum of the ear. There are other, smaller 
membranes, on the side of the tympanum, next to the inner 
ear, which separate the middle from inner portion of the ear. 
The outer membrane of the tympanum, and one of the inner 




Diagramatic Section of Left Ear.— 1. Concha. 2. External canal. 3. Middle ear, crossed by 
the ossicles. 4. Inner ear. 5. Petrous bone. 6. External membrane of the middle ear. 7. Eustachian 
tube. 8. Auditorv nerve. 



membranes are joined by a very crooked line of tiny bones, 
called the ossicles of the ear. 1 A small air tube, called the 
eustachian tube, or internal auditory canal, leads from the 
tympanum to the pharynx, so that the air in the tympanum 
may pass in or out. The tympanum is to convey the sound 
from the outer to the inner ear. 

The inner ear is a very singularly-shaped chamber in the 
petrous bone. This chamber is filled with a watery fluid, 



132 PHYSIOLOGY. 

and has in it the membranes on which the nerves of hearing 
are spread out. It is the most important part of the ear. 
The other portions may be destroyed, and yet the person 
can hear quite well by this portion alone. This inner ear 
consists of several parts, which seem designed for different 
purposes in hearing. 2 

145. How We Hear. — As in seeing, so it is in hearing. 
The objects which produce the sounds we hear do not come 
into the ear and touch the nerves of hearing, but sound 
comes from them into the ear, somewhat as light comes 
into the eye. 

146. Sound. — When any elastic body, such as a bell, 
drum, or piano string, is struck, it vibrates very rapidly. 
The air which surrounds the vibrating, or sounding body, is 
elastic too, and is caused to vibrate as the bell does. The 
vibrations in the air pass out from the bell in all directions 
in waves. If these waves enter the ear, and cause the air 
of the outer ear to vibrate, the vibrations will be conveyed 
through the tympanum to the inner ear. The watery fluid 
of the inner ear will vibrate in like manner, and thus irritate 
the nerves of hearing so as to produce those sensations on the 
brain that the mind learns to know as sound. By practice, 
the mind learns so tell much about the nature of the sound- 
ing body, to tell its direction, and something about its 
distance. 

147. Hygiene of the Ears. — The ear is more liable to 
disease than the eye is. Inflammation of the throat often 
affects the ear through the eustachian tube. It is some- 
times injured by the lodgment of objects in the outer ear. 
The bitter wax of the outer ear is designed to protect the 
ear from insects. This wax will come out of itself, so that 
the person need not try the experiment of picking it out. 
The ear should not be exposed to great cold, nor to draughts 
of cold air. Deafening sounds sometimes injure the ear. 
Under no circumstances should any one be struck on the 



HEARING. 



n$ 



ear. To strike the ear with the hand, or with a book, is 
liable to injure the tympanum seriously. 

Deafness is a very great misfortune. The mind loses one 
of its chief organs of sense in losing the hearing. It is 
through hearing that we learn to use language. Any one 
who is born deaf, is dumb also. Any one who loses the 
sense of hearing, soon loses the power to modulate the 
voice, for the voice is guided by the ear. Such persons 
suffer great loss of enjoyment. 



Notes. 

i. The bones of the middle ear form a very irregular chain 
of bones, connecting the external membrane with the membrane 
of the inner ear. They seem designed to aid in hearing, by form- 
ing a better means of transmitting the waves of sound. They may 
be removed, and the hearing be retained. There are four of these 
little bones in each ear: (i) Mallet, (2) anvil, (3) orbicular, and 
(4) stirrup. They are joined by cartilage, and are acted upon by 
small muscles that enable us to make the chain press firmly against 
the membranes, as we do in straining the ear to hear sounds that 
are difficult to catch. 

2. The inner ear is the essential part of the organ. It is a 
cavity filled with fluid. This fluid is water, with some salts dis- 
solved in it. The cavity is exceedingly complex in shape, and pre- 
sents many winding canals and passages. Floating in the fluid 
that fills the cavity, there is a sack, upon the walls of which 
the ends of the auditory nerves are exposed. The auditory 
nerve enters the inner ear from the rear, and sends its various 
fibers to the different parts of the cavity. Near the membrane, 
against which the stapes, or stirrup bone, fits, the cavity of the 
inner ear is large. This large part seems designed to receive the 
ruder sounds. The cochlea of the inner ear contains a thin, bony 
plate, triangular in shape, across which are drawn nerve fibers of 
different lengths, somewhat like the wires of the harp or piano. 
This portion of the ear seems designed for the appreciation of musical 
sounds. 



134 



PHYSIOLOGY. 



Suggestive Questions. 

Why do we have two ears? What are the parts of the ear ? Which 
part is the real ear? How are we liable to injure the ear? What is 
sound? Which affects the mind the more, blindness or deafness? 



Topical Outline. 



Special 

Sensibility. 

a. General sensibility. 

b. Portions especially sensitive. 

c. Excessive irritation produces 

pain. 
(i) Causes of pain. 
(2) Uses of pain. 
Special senses. 

a. Touch. 

(i) Possessed by the skin. 
(2) The hand is the special 
organ. 

a. Adaptation of hand for 
touch. 

b. Ideas gained through 
touch. 

c. Education of the sense 
of touch. 

b. Taste. 

(1 ) Limited to the mouth. 

(2) The tongue is the special 
organ of taste. 

(3) Uses of the sense of taste. 

(4) Education of taste. 

(5) Injuries to taste. 

c. Smell. 

(1) The nose is the special 

organ. 

(2) The uses of the sense. 



Senses. 

d. Sight. 

(1) Nature of light. 

(2) The eye. 

[a) Protecting parts. 

(b) Eye balls. 

(1) Coats. 

(2) Humors. 

(3) Muscles. 

(3) Theory of seeing. 

(4) Defective vision. 

a. Near-sightedness. 

b. Far-sightedness. 

(5) Causes of injury. 

(6) Means of recovery. 

e. Hearing. 

( 1 ) Nature of sound. 

(2) The ear. 

(a) Outer. 

(1) Structure. 

(2) Uses. 

(b) Middle. 

(1) Structure. 

(2) Uses. 
(<r) Inner. 

(1) Structure. 

(2) Uses. 

(3) Theory of hearing. 

(4) Liability of organ to in- 
jury. 

(5) Care of organ. 



■ i. ■ ■. 



■■ 



CHAPTER XVI. 

ELEMENTARY SANITARY SCIENCE. 

148. What and How to Eat.— The effects of food 
upon the health are direct and powerful, for the food either 
nourishes and revives the system, or it may, by its unfit- 
ness, cause disorder and disease. 

If the quantity taken is much in excess of the demands 
of the system, evil consequences follow. Over-eating pro- 
duces dullness, heaviness, and tendencies to sleep. Over- 
taxing the digestive organs, deranges their action and causes 
dyspepsia. Excess of food in the intestines, causes irrita- 
tion. 

If too little food is eaten, the strength of the system fails. 
The mind, too, loses in force. 

One who labors needs sweet, light bread, lean meat, eggs, 
milk, beans, and similar articles of food. Fruits and grains 
serve well for those who labor less violently, and to complete 
the diet of the laborer. Avoid heavy bread, rancid or 
offensive butter, sodden potatoes, tainted meats, foods fried 
in grease, excessive quantities of pickles and condiments. 

The system is disposed to accommodate itself to custom. 
If the meals occur at regular intervals, the digestive organs 
will find proper seasons of rest and action. Hurried eating is 
an evil. The food bolted into the stomach, partially chewed, 
gives to the stomach a task for which it is unfitted. Food 

(135) 



13* 



PHYSIOLOGY. 



thus eaten, gives little satisfaction, and often proves to be a 
source of irritation. 

If food is eaten under mental depression, ill-humor, or 
anxiety, digestion does not proceed as well as if the food is 
eaten in cheerfulness, deliberation, and peace. The sur- 
roundings of the table and room need to be graced with 
cleanliness and taste. Each person needs to learn for him- 
self what food best suits his needs. All need to observe the 
following simple rules: (i) Eat liberally and regularly of 
plain food ; (2) eat deliberately, and with pleasant surround- 
ings; (3) eat sparingly of highly-seasoned mixtures; (4) cease 
eating before the appetite is entirely satisfied, rather than eat 
too much. 

149. What to Drink. — The system demands water. 
This demand is more urgent than the want of food. All 
substances added to water affect its purity and usefulness as 
drink. Of pure water, a person is not disposed to drink 
too much, and there are no serious consequences from an 
excess of water in the system. Water is easily excreted, 
and does not tend to inflame or irritate. Too little water 
causes thirst, which will give no rest until relieved. 

Dangers arise from the impurities contained in the water 
we drink. Water containing much mineral salts, such as 
lime, iron, or common salt, is unfit for use. Water having 
bad odor or taste, or water that is colored, or water that 
will produce a scum when boiled, is unfit to use. Dyspepsia, 
dysentery, diarrhea, and typhoid and malarious fevers are 
often caused by the use of impure water. When pure 
water can not be obtained, the water that is used should be 
filtered or boiled. 

Much drink at meal time weakens digestion. Much tea 
and coffee dilute the juices of the stomach by the amount 
of water they contain. They affect the nervous system by 
the stimulants they contain. They tend to deaden the 
nervous sensibilities. The fact that these substances produce 



ELEMENTARY S. IX/V. \RY St 'IF. XL 'E 



137 



a craving so strong that persons who use them habitually 
find it difficult to cease using them, shows how decidedly 
they act on the nerves. 

A moderate quantity of warm drink, taken with the food, 
may assist rather than retard digestion. If the food is eaten 
deliberately, there will be little call for copious drinks of 
of water, milk, tea, or coffee. To drink hastily large quan- 
tities of cold fluid deranges digestion. Ice water is too 
cold for use. 

To use beer, wine, or whisky, in any of their forms, is 
useless and dangerous. The craving which these substances 
beget in the system, is a sure evidence of their powerful 
narcotic influence. 

150. The Clothing and Cleanliness. — Properly nour- 
ished and cleaned, the system is healthy and vigorous. If 
either of these two processes is arrested, or is imperfectly 
performed, the result is weakness and disease. Disease is 
not something which comes upon us from the outside, 
but is the result of faulty nutrition or defective removal 
of waste matter. 

The skin is specially engaged in the excretion of matter. 
To keep the skin clean, by proper bathing and clothing, is 
to keep open one of the chief outlets from the system. 
The warm bath with soap, followed by brisk rubbing, opens 
the pores and removes the waste matter from the surface. 
Exercise in the sunlight and fresh air enlivens the skin. 

The clothing absorbs the impurities from the skin-, and 
becomes loaded with them. Especially is this true of the 
under-clothing. The garments worn next to the skin should 
be frequently removed, washed, and aired. The same is 
true of the clothing of the bed. 

Warmth is better attained by putting on several layers 
of light, loose-fitting garments, than by fewer layers of heavy 
clothes. The clothing should be loose, because it is warmer, 
and that it may not press the body out of shape. Tight 



I3 8 PHYSIOLOGY. 

clothing prevents free circulation of the blood, by pressing 
on the arteries and veins. Clothing that fits closely about 
the waist should not be worn, because it hinders the fullness 
of breathing. The weight of the clothing should be borne 
by straps across the shoulders, rather than be supported by 
tight bands about the waist. 

The clothing should protect the extremeties. The ex- 
posure of hands, wrists, feet, ankles, and legs is a frequent 
cause of congestion and "cold." Children who are well 
clothed grow more rapidly and more fully than those who 
are not. The naked legs and arms, and the tight waists 
of children, which so please the vanity of silly mothers, are 
at the expense of the health and development of the 
children. 

A few suggestions are worthy of repetition : Keep the 
skin clean; dress the body warmly; change the clothing 
frequently, especially the underwear; avoid damp clothing; 
exercise much in the fresh air and sunlight. 

151. Breathing and Pure Air. — The proper oxidation 
of the blood depends on the purity of the air and the full- 
ness of respiration. If we keep the chest large, and breathe 
deeply, we shall obtain more oxygen than if the lungs are 
compressed in any way. Tight clothing about the chest 
prevents the chest from expanding, and, therefore, causes 
us to breathe less air. Such clothing also prevents the lungs 
from developing, and makes them small and feeble. If we 
sit or* stand with the shoulders drooped forward, the chest is 
diminished in size, and less air is breathed; we should, 
therefore, keep the shoulders well back, and sit or stand in 
an erect position. 

The in-door air of houses is less pure than the free air 
outside. The oxygen within is rapidly consumed by the 
breathing of the inmates, and by the burning of fires, 
lamps, and gas-jets. Impurities are thrown into the air by 
the breath, and the escape of other waste matter from the 



ELEMENTARY SANITARY SCIENCE. 



T 39 



bodies of persons. Lamps usually throw their impurities 
into the air of the room. Other impurities arise from the 
cooking and the decomposition of substances. 

The outdoor air is usually pure. In order that there 
may be sufficient interchange of the air within with that 
which is without, there must be ventilating passages. The 
good health of the inmates is impossible without ventila- 
tion. 

Those who live exclusively in-doors can not be so healthy, 
robust, and vigorous, as those who live more in the open 
air. 

The breathing of impure air tends to cause headache, 
drowsiness, languor, mental confusion, and loss of appetite. 
Persons who breathe impure air become pale, chilly, and 
feeble. The breathing of pure air produces warmth, gives 
a rosy tinge to the skin, causes clearness of mind, sharpens 
the appetite, and increases the general activity of the 
system. 

A few words of advice are worthy of being remembered 
and heeded : Do not close the sleeping and sitting-rooms so 
that no fresh air can enter; breathe fully; keep the shoul- 
ders back, and the chest extended; live much in the open 
air. 

152. Occupation. — It is the universal experience, that 
regular exercise tends to promote health. Those who have 
work to do are usually more regular in their habits, both of 
body and mind, than are those who are idle. The laborer 
is usually blessed with a keen appetite; indigestion gives 
him little trouble. He rests well, and is free from the many 
imaginary pains and ills that afflict the idle. Diligence and 
industry give peace of mind, and tend to long life. 

It is by proper exercise and nutrition that any part of the 
body is made strong. The laborer is strong ; the idle person 
is usually weak. The muscles of the working man are hard 
and dark, those of the idler are soft and pale. The mind 



1 4 PHYSIOLOGY. 

of the workman is clear and forcible, the mind of the idler 
tends to confusion and feebleness. 

It is not all kinds of occupation that conduce to health. 
If the business in which any one is engaged is exclusively 
of one kind of work, and calls into action only one part 
of the organism, while other parts suffer from inaction, the 
occupation may be injurious rather than beneficial. Work- 
men who perform their labor in crowded factories, or in 
rooms that are illy lighted or ventilated, may suffer disease 
from too close confinement. In many kinds of industrial 
pursuits, the workmen are compelled to inhale injurious dust 
and gases produced from the substances in which they work. 
Such persons frequently suffer disease from these causes. 
In many kinds of business, workmen are compelled to sit or 
stand, with little exercise, during the entire day. Sedentery 
employment should be preceded and followed by long walks 
in the open air. 

Whatever be the circumstances, a person needs something 
regular to do. The task . needs to be one that engages the 
energies of both body and mind in a way that is pleasant to 
the individual. Besides the manual labor that each may 
profitably perform, great benefit will come from giving a 
short time daily to the pursuit of some kind of study, or 
artistic avocation, that shall gratify the higher wants of 
the mind. A person who can each day devote a short 
time to the gratification of some taste for the pleasing or 
beautiful, will feel a keener relish for life, than he who gives 
the whole time to drudgery or idleness. 

In connection with occupation, which shall provide regu- 
lar hours for labor, there needs to be found time for recre- 
ation. "All work and no play" tends to make the person 
dull. A few minutes of amusement, of play, or delightful 
freedom, invigorates the whole being. 

Strength of body and mind requires that they shall 
be used, rested, and recreated. Diligence is a powerful 



ELEMEN TAR V SAX J TA Y SCIENCE. T 4 T 

barrier to disease. Idleness opens the gates for a score 
of ills. 

153. Habits. — Both the body and the mind are disposed 
to repeat former actions under like circumstances. It is in 
this way that we form habits; i. e., by doing a certain thing, 
we are disposed to do it again, and, by repetition, the ten- 
dency to do it becomes so strong that it is difficult for us to 
avoid doing it. It is in this way that we learn to perform 
difficult tasks easily. Some movement of our hands may be 
difficult at first. If we repeat the effort many times, the 
movement becomes quite easy, and, finally, we may perform 
the action without giving it any thought. 

In like manner, the system is easily impressed by sub- 
stances that have peculiar effects on the nervous system. 
By using small quantities of tea, coffee, alcohol, tobacco, or 
opium, we may form a demand for them, until we find that 
our system craves them. At first the system may reject the 
substances, yet repetition may cause us to lose our dislike, 
and, finally, to enjoy their influence. At first tobacco causes 
nausea, but, by repetition, the person learns to like it, and at 
last becomes a slave to the use of it. 

By neglect, we may form evil habits that lead directly 
toward disease ; whereas, by attention, we may form 
such habits as shall lead" to health. By persistent effort, 
we may correct our evil habits, and substitute for them 
tendencies toward good. One who uses tobacco, may 
lessen the amount gradually, and, by firm resolution, re- 
frain from its use until the system becomes accustomed to 
doing without it. 

Even if we fail at first to accomplish a desired end, 
we may have so gained in strength by the effort that 
later attempts may prove successful. There is reason for 
great faith in final success in all efforts to correct evil pro- 
pensities. It is by neglect and repetition that what is evil 
and injurious gains dominion over us. 



142 



PHYSIOLOGY. 



154. Care of the Sick. — The room in which a person 
is sick should be well-lighted, without the direct light pain- 
ing the eyes of the sufferer. The room should be well 
ventilated, without the draught of air being felt by the 
invalid. A thermometer should be employed, by which to 
tell* the temperature. The temperature should not vary 
much from sixty-eight degrees. 

The room should be free from noise and excitement of 
any kind. There should be no bustle of cleaning; no slam- 
ming or creaking of doors; no mysterious whisperings. 
Whatever is said in the room should be told in an ordinary 
tone of voice. 

The bed should be comfortable, and the patient be as 
little disturbed in position as possible. The clothing of the 
bed should be kept clean, and every thing offensive be re- 
moved promptly from the room. 

The patient's food should be prepared in a plain but 
inviting manner, without tempting the appetite. Trust to 
nature to manifest her wants. The invalid is not hungry, 
and is quite likely unable to digest food. Small quantities 
of easily digested food, taken quite frequently, are usually 
better than to take larger quantities at a time. 

The nurses need to act naturally, and not to tire the 
patient with anxious movements, restlessness, and officious 
care. Trained nurses, who have in mind simply the faithful 
discharge of duty, are to be preferred to persons whose 
excessive anxiety unfits them for the quiet care of the sick 
person. 

The sick one needs peace of mind, quiet, and rest ; these 
can only be afforded by quiet nursing. Medicine may be 
needed at times, to assist nature in recovery; usually, how- 
ever, proper rest, cleanliness, plain nourishment, and relief 
of mind are the chief agents in recovery. 

When the patient becomes convalescent, he needs to 
be guarded against excessive exercise, against too much 



ELEMENTAR Y SAN I TAR Y SCIENCE. 



*43 



excitement, and against immoderate eating. "Make haste 
slowly " in recovery. 

Those who serve as nurses should be careful to rest them- 
selves at regular intervals, to eat regularly and liberally, and 
to avoid all excessive anxiety of mind. Nursing the sick is 
laborious service, at which a person may easily over-work. 

155. General Suggestions. — To maintain good health, 
we should observe the following suggestions : 

1. We should take a proper amount of exercise. 

2. We should take proper rest and sleep. 

3. W T e should eat liberally of plain, good, well-cooked 
food. 

4. We should use pure water. 

5. We should breathe fully of pure air. 

6. We should attend regularly to the excretions from the 
body. 

7. We should keep the skin clean. 

8. We should wear clean clothing, that will protect from 
heat or cold. 

9. We should wear such clothing, and maintain such 
position, as will give the body entire freedom of action. 

10. We should avoid chill, and not wear damp clothing. 
The feet and hands should be kept warm and dry. 

11. We should be regular and moderate in all our habits. 

12. We should keep the mind at peace with itself and 
with all men. 



Suggestive Questions. 

How may disease result from the food we eat? What substances 
should we avoid as food? How is the appetite affected by the mind? 
What rules would you give about eating? 

What dangers are connected with drink? What diseases, often 
arise from drinking impure water? How may we judge of the purity 
or impurity of water ? How may impure water be purified? What 



I44 PHYSIOLOGY. 

are the objections to the use of tea and coffee? Why should we not 
use beer, wine, or whisky ? 

What is disease ? Does it come upon us from within or from 
without? What are the great causes of disease? Why should we 
keep the skin clean ? Why should we wear clean clothing ? Which 
clothing needs the greater care, the underwear, or the outer gar- 
ments? Why should we wear loose clothing? Why should the 
clothing be supported by straps over the shoulders ? How does 
improper clothing hinder the growth of children? What special 
objection is there to the wearing of damp clothing? 

How may we enlarge. the lungs? Why are in-door dwellers less 
robust than those who live much in the open air? What are the 
diseases that are caused by impure air? What rooms require special 
attention in ventilation? Give three directions as to the manner 
of breathing. 

What effect has regular occupation on the health ? How do dili- 
gence and industry affect the mind? Why are idlers usually dissatis- 
fied? In what way do some kinds of occupation prove to be 
unhealthful ? What need is there of recreation ? Why should we 
play ? 

What is habit ? How are habits formed ? How may we over- 
come bad habits ? What is gained by trying, even if we do not 
succeed ? 

How should the room of a sick person be lighted ? How should 
it be aired? What need is there of a thermometer in it? What 
should the attendants avoid ? What directions need to be observed 
about the bedding? How should the food for the invalid be pre- 
pared ? How should the nurse behave ? What enables the sick 
person to get well ? When the invalid is getting well, what mistakes 
is he liable to make ? What care should the nurses take of them- 
selves? State twelve directions for keeping well. 



CHAPTER XVII. 

EMERGENCY AND ACCIDENT. 

156. In case of sickness, seek a comfortable room, 
well lighted and ventilated. Keep warm, clean, and quiet. 
Usually the system will recover its natural condition quite 
soon if undisturbed. Do not be too anxious, nor treat your- 
self with copious amounts of medicine. If you are very ill, 
send for a competent physician, and wait quietly for his 
arrival. 

157. If serious accident occur, place the unfortunate 
person in the most comfortable position possible, with 
sufficient fresh air and warmth. Relieve acute pain by 
applying hot or cold compresses to the injured part, as may 
feel most agreeable to the sufferer. Send for a surgeon, and 
send such information as may enable him to judge what 
appliances to bring with him. 

158. If bones be broken, joints dislocated or sprained, 
place the injured part in the least painful position. Keep 
the part quiet. Relieve acute pain by applying hot or cold 
water. Keep the feet warm. Obtain the services of a 
surgeon, to replace the parts in their natural position, and 
to apply bandages for retaining them in place. 

159. If wounds be made which bleed rapidly or in 
jets, pressure must be made upon the veins or arteries that 

Pgy.-io. (i 45 ) 



■^■M 



146 



PHYSIOLOGY. 



are cut. Pressure may be made with the thumb, or with a 
knotted handkerchief bound around the limb, so that the 
knot rests over the vein or artery; after tying the ends, 
twist the handkerchief tightly. If the bleeding is from an 
artery pressure must be made between the wound and the 
heart; but, if from a vein, make pressure at, or beyond, 
the wound. 

If the bleeding is moderate, bathe the wound freely with 
cold water, place the edges of the parts together naturally, 
and retain them in this position with strips of sticking- 
plaster and light bandages. Keep the wound quiet, that 
it may heal. Avoid salves and ointments. 

160. In burns and scalds, cut the clothing quickly 
and gently away, and coat the injured part thoroughly 
with water and flour, water and soda, or sweet oil and 
cotton. Immerse the part in cold water, if convenient. 
Do not apply salves and ointments. Keep the injured part 
clean and quiet. 

161. In cases of apparent death by drowning, treat 
the case at once. Strip the clothing from the throat and 
chest. Apply diluted ammonia to the nostrils at intervals. 
Place the person gently on the face, with the forehead rest- 
ing on the arm, so that the entrance to the windpipe may 
be open. Turn the body upon the side, and again upon 
the face, alternately, every four seconds. When the body 
is turned upon the face, make gentle pressure over the chest 
to aid in expelling the contents, and remove such pressure 
upon turning the body on the side, in order that the chest 
may fill with air. Persevere in this movement for two or 
three hours, or until the patient begins to breathe. Chafe 
the skin, and rub the limbs firmly toward the heart. Re- 
move the wet clothing of the sufferer, and replace it with 
warm, dry wrappings of any kind. 

162. In cases of suffocation from foul air, remove 
the body into fresh air, and treat as for drowning. 



■Mm 



EMERGENCY AND ACCIDENT. 



147 



163. In cases of unconsciousness from cold, rub 
the body with snow, or place it in water for a short time. 
Rub briskly, until dry. Keep up warmth by friction. Keep 
the patient in a cool room. Give small quantities of mild 
stimulant. 

164. Starvation may be relieved by at first giving very 
small quantities of mild food, at frequent intervals. A full 
meal should not be given for some time. Keep the body 
warm. Give water to drink freely. 

165. Sunstroke is caused by excessive heat. If a per- 
son fall under such prostration, the skin will be "burning 
hot." Apply cold water at once, first to the head, then to 
the chest, and then to the extremities. Repeat the opera- 
tion until consciousness is restored. 

166. If the clothing catches fire wrap the body in a 
shawl, coat, blanket, or any such article, to extinguish the 
flames. If no wraps are near, roll on the ground or floor. 
Wet the clothing. Do not run in the open air. 

167. To escape from a burning house, keep the doors 
and windows closed. If the smoke is great, remain near 
the floor. If you must pass through flame, wrap the body 
in a blanket. To protect the face and lungs, draw a wet 
woolen stocking over the head and face. Do not jump from 
the window. Tie the bed-clothing together at the corners, 
to make a long rope, fasten one end to the bed, and let 
yourself out and down from the window, by climbing along 
this rope. 

168. Choking may usually be relieved by smart blows on 
the shoulders. 

169. In case of diarrhea, go to bed, keep warm, and 
lie quietly on the back. Rest is better than medicine. Eat 
sparingly. Use no solid food. 

170. If bitten by a snake or mad dog, wash the 
wound thoroughly, or suck it strongly. Rub it with caustic 
soda or carbolic acid, or burn it with an iron heated 



148 PHYSIOLOGY. 

\ 

"white hot." Whisky drank freely proves to be a useful 
remedy. 

171. Poisons. — Many poisons so closely resemble arti- 
cles in common use that all dangerous substances should be 
plainly marked, and all unknown substances should be 
destroyed. When healthy persons are taken ill, severely 
and suddenly, soon after swallowing some substance, it is 
probable that it is the effects of poison. In cases of poison- 
ing, empty the stomach promptly. This may be done by 
drinking a cup or two of warm water, in which has been 
stirred a tablespoonful of ground mustard or common salt. 
The vomiting should be continued until the stomach is thor- 
oughly emptied. Besides emptying the stomach, the effects 
of the poison may be counteracted by the action of some 
substance of a different nature. The following antidotes 
may be used: 

The acids most likely to be used as poisons are muriatic, 
nitric, and sulphuric. These acids, if swallowed, destroy the 
mucous membrane of the stomach, and, in sufficient quan- 
tities, they will corrode the entire walls of the alimentary 
canal. The antidotes are the various alkalies, such as strong 
soap-suds, chalk, saleratus in water, and lime-water. 

The alkalies most likely to be used as poisons are am?nonia, 
and some forms of potassa. These substances burn the walls 
of the alimentary canal. The antidotes are the vegetable 
acids, given in dilute form, such as weak vinegar, or tartaric 
acid dissolved in water. Oils, such as castor oil, linseed oil, 
sweet oil, or cream, may be used to antidote the alkalies. 
Vomiting should be caused afterwards, to relieve the stomach 
of its contents. 

Alcoholic liquors are poisonous, and, when they cause 
intoxication, the stomach should be emptied by vomiting, or 
by the use of a stomach-pump. Many compounds of copper 
are poisonous, and copper vessels should not be used, 
therefore, in cooking. 



EMERGENCY AND ACCIDENT. 



149 



Common arsenic, in any of its forms, such as white arsenic, 
Wowlet's solution, or Paris green, is a horrid poison. To 
relieve it, cause vomiting by the use of mustard or ipecac. 
The antidote is the hydrated peroxide of iron. Use lime- 
water if Fowler's solution has been taken. 

Sugar of lead (acetate of lead) and white lead are poisons. 
Beside vomiting, use epsom salts as an antidote. 

Any of the mercurial preparations are poisonous. Use 
white of eggs and milk as antidotes. 

The most common narcotic poisons are opium y aconite, 
belladonna, hemlock, digitalis, tobacco, mix vomica, and strich- 
nine. Empty the stomach by using mustard or alum. Give 
strong coffee. Keep the sufferer in motion as much as 
possible. With nux vomica and strichnia allay spasms by 
use of chloroform. 



Suggestive Questions. 

What is sickness ? What does the sick person need ? What are 
the objections to the use of a small, dark room for the sick? If a 
person is suffering severe pain, how may you relieve it? Why should 
broken bones be held in natural position while mending? How may 
you know that an artery is cut? Where must pressure be made 
to stop the bleeding of arteries ? How may you stop the pain 
of a burn or scald ? How is death caused in cases of drowning ? 
What do you think is the condition of the lungs of the person 
who is drowned ? How may breathing be restored ? Why does foul 
air suffocate? 

How would you restore one to life who is nearly frozen to death? 
Why will green leaves or a damp cloth worn in the hat aid in pre- 
venting sunstroke ? How may you put out the fire, if your own 
clothing is burning ? How may you escape from a burning house ? 
How should you treat diarrhea? If you receive a poisonous bite, 
how would you treat the wound? What are the symptoms of poison- 
ing? If persons have swallowed poison, what is the first thing to be 
done ? In what ways may vomiting be caused ? What common 
acids are poisons ? What common alkalies will antidote these poi- 






*5° 



PHYSIOLOGY. 



sons ? If strong lye or other alkalies be swallowed, what common 
substances may be used to prevent their injurious effects? Why 
should all substances that are kept about the house be plainly 
marked? Why should we not use copper or leaden vessels for cook- 
ing purposes? 



SUPPLEMENT 



(151) 



ALCOHOL. 

ITS EFFECTS ON BODY AND MIND. 

172. Alcohol. — The fluid commonly known as alcohol 
is produced by the fermentation of sugar. Sugar is a 
vegetable product; so also is starch. Since starch can be 
converted into sugar (Note 2, Chap. VII.), these two sub- 
stances may be viewed together as the usual sources from 
which alcohol is produced. The starch and sugar used for 
this purpose are derived from various fruits, grains, and 
tubers, such as the apple and grape, corn and rye, potato 
and beet. Vast quantities of these articles, so commonly 
used for food, are employed each year in the making of 
alcohol. 

173. Fermentation. — The process by which alcohol is 
made from sugar is called fermentation. The sugar is de- 
composed, so that it ceases to be sugar, and becomes two 
other substances: (1) A volatile fluid, called alcohol; (2) a 
gaseous fluid, called carbonic acid. Sugar does not of itself 
readily decompose, but when certain substances are put with 
the sugar, it speedily undergoes change. The juice of apples 
is sweet when first made into cider. It is sweet because of 
the sugar in it. If the cider is kept at a summer temper- 
ature, it rapidly undergoes a change, by which bubbles of 
gas arise from it, and it loses its sweetness and acquires a 
very different taste and odor. The sugar in the cider 

(153) 



I 54 PHYSIOLOGY. 

changes to carbonic acid, which forms the bubbles of gas, 
and to alcohol, which gives the new taste and odor. 

If we take a few drops of ordinary molasses and mix with 
it some warm water and a few grains of common baker's 
yeast, the sugar of the molasses will turn to carbonic acid 
and alcohol. 

If such grains as wheat, barley, and corn are kept moist 
and warm, they will begin to grow. If we chew these grow- 
ing grains we shall find them to be sweet. Their starch has 
partly turned to sugar. If they were fermented while in 
this condition, their sugar would produce alcohol. 

Almost all the alcohol that is produced by man is made in 
ways like these we have just described, only on a very large 
scale. It is in such ways that the alcoholic beverages, 
enumerated in Note 7, Chapter VI. , are made. 

174. Distillation. — Alcohol boils at a lower temperature 
than water does. By heating a mixture of water and alcohol 
until it is above the boiling point of alcohol, but below the 
boiling point of water, we may drive the alcohol off in the 
form of steam, and have the greater portion of the water 
left behind. If this steam is condensed in a cold vessel, we 
shall have all of the alcohol and some of the water. This 
process is called distillation. In this way distilled liquors 
are made from fermented liquors (Note 7, Chapter VI.). 

175. Properties and Uses. — Alcohol resembles water 
in appearance. It is lighter than water. It has a mild odor 
and a pungent taste. It is very volatile, and burns readily. 
It will dissolve gums, oils, and resins; hence it is much used 
in making varnishes. Because of its power of dissolving 
gums and oils, it is used in extracting these substances from 
various leaves, barks, seeds, and roots, so that a large class 
of alcoholic tinctures are thus made. 

The use of alcohol in the preparation of beverages is by 
far its greatest use. Almost all beverages that intoxicate 
owe that property to the alcohol they contain. Beer, wine, 



ALCOHOL. 



J 55 



and whisk}- owe their intoxicating effects to the alcohol they 
contain (Article 51, and Note 7, Chapter VI.). 

176. Alcohol as Drink. — It has been stated in Article 
50, how largely the body is composed of water, and how 
urgent is the demand for drink. 

A proper drink is such as will supply the demand for 
water, without introducing any hurtful substances. The 
universal drink is ordinary water. This seems to be the 
natural drink. Water quenches thirst, and fills the different 
parts of the system with their needed quantity of liquids. 

If substances that have a great attraction for water are 
taken into the body, they will draw the water from the 
various tissues. If the attraction is great enough, they will 
decompose the tissues. Substances that are called caustics 
destroy the flesh by their intense attraction for the water in 
the flesh. Common lye, lime, sulphuric acid, and carbolic 
acid destroy flesh in this way. 

Substances having a milder attraction for water do not 
destroy the tissues, but draw the free water from them. This 
causes the tissues to shrink, to harden, and to stiffen. Sub- 
stances of this kind, whether taken as drink or food, 
produce thirst. Common salt and alcohol act in this 
manner. 

If the strongest form of alcohol is taken into the mouth 
or stomach, it will blister the mucous membrane, and de- 
compose the structure of the parts, so great is its affinity for 
the water they contain. If dilute alcohol be introduced, the 
same kind of action occurs in less degree of violence. 
Thirst is always produced by the drinking of any kind of 
alcohol. A natural drink always slakes thirst. The large 
amount of water in some drinks, with the small portion of 
alcohol they contain, enables them to allay thirst; such is 
the action of beer. It is the water, however, and not the 
alcohol, that gratifies the thirst. The water of the beer 
would quench the thirst more readily if the alcohol were 



156 PHYSIOLOGY. 

not present. Examinations prove that the tissues of those 
who are addicted to the use of alcoholic beverages are hard- 
ened by the loss of their water. This is especially true 
of the nervous tissue of those who die from the evil effects 
of alcohol. 

It is the purpose of the circulatory fluids to aid in digest- 
ing the food and to hold the food particles in solution. 
Alcohol, if used in other than extremely small quantities, 
tends to hinder the digestion of food, and to make the 
albuminoids less easily dissolved. By the action of the 
alcohol on the nerves and muscles of the stomach, the opera- 
tions of the stomach are less vigorous. Alcohol seems to act 
as the reverse of a proper article of drink. It is a mistake 
to think that alcohol is a true beverage. 1 

177. Alcohol as Food. — Food gratifies hunger, and 
maintains the strength, warmth, and vigor of the body. 
If alcohol is taken into the alimentary canal, it passes 
directly into the blood, and is distributed throughout the 
body. It goes into the blood as alcohol. It is distributed 
as alcohol. It is finally cast out of the body as alcohol. 
It undergoes little or no change in the body. It does not 
appease hunger. It does not supply any lasting strength to 
the tissues. Food and alcohol are directly opposite in their 
action. It is a mistake to suppose that alcohol is a food. 1 

178. Alcohol as a Heat-producer. — The body must 
be kept warm. This is done by the union of the oxygen we 
breathe with certain substances in the blood. This kind of 
burning produces carbonic acid. If there is much heat 
produced, there is much carbonic acid formed. All heat- 
producing articles of food incline to increase the warmth 
of the body. If the oxygen were to act on the alcohol as 
it does on other substances in the blood, much warmth 
would thereby result, and much carbonic acid would be 
formed. The facts are, however, that, since alcohol under- 
goes little or no change in its passage through the circula- 



ALCOHOL. 



*57 



tion and the tissues, the quantity of carbonic acid exhaled 
from the lungs of a man under the influence of alcohol is 
much less than the amount from the same lungs when 
the man has no alcohol in his system. The temperature 
of the body is lowered, rather than raised, by the action 
of alcohol. 2 

Dr. W. B. Carpenter says: "For a few minutes after 
alcohol is administered, to the amount of a gill of wine or 
brandy, the temperature rises slightly, after which it falls 
several degrees below the standard of health, and remains 
so for hours." 

Heat-producing foods increase the strength and vitality, 
and enable us to withstand great cold. 

Dr. Austin Flint says: "It is not proved that alcohol 
enables men to endure a very low temperature for a great 
length of time. This end can be accomplished only by an 
increased quantity of food." 

If alcohol tends to lower the temperature of the body, 
and to make men less able to withstand exposure to low 
temperature, it must be a mistake to regard alcohol as a 
heat-producer. 

179. The Effects of Alcohol on the Blood. — Alcohol 
holds to the blood, because the blood is so largely composed 
of water. The alcohol causes the corpuscles to shrink and 
to become wrinkled and ragged. By this action, the cor- 
puscles can not perform their purposes so well. They can 
not so well carry oxygen to the tissues, nor bear away the 
carbonic acid from the system. 

The fibrine of the blood is injuriously affected by alcohol. 
The blood of persons who are addicted to the use of alco- 
holic liquors does not coagulate naturally. 

The habitual presence of alcohol in the blood injures the 
blood itself, and also causes the great organs of circulation 
to become diseased. The heart and liver especially become 
weakened and diseased. 



158 PHYSIOLOGY. 

Because of the injurious effects of alcohol on the blood 
and organs of circulation, persons who use it freely as a 
beverage are likely to become diseased. They suffer be- 
cause the impurities of the body are not removed promptly, 
and because digestion and circulation are not performed 
naturally. Such persons are less able to withstand hard- 
ship, and are more likely to take diseases in case of 
epidemics. 

180. Effects of Alcohol on the Nerves. — The nerves 
lead from the brain to all parts of the body. It is through 
the nerves that we move the muscles, and by them that we 
feel. Whatever affects the nerves affects our power to move 
and to feel. The brain appears to be the instrument most 
closely connected with the mind. Whatever affects the 
nervous system affects the mind. Motion, feeling, and 
mental action arc all dependent on the nervous system. 

Alcohol has very decided effects upon the nerves and 
brain. 3 When alcohol comes in contact with nerves, it 
causes them to contract and to become more hard. The 
nerves and brain of persons who die from the effects of 
alcohol are noticeably hardened. By this change in the 
nerves, they become partially paralyzed, and unfit for their 
purposes as feelers and movers. If we hold alcohol in the 
mouth for a short time, we can not taste so acutely after- 
wards, because the nerves of taste are somewhat deadened 
by the alcohol. If we hold alcohol in the mouth about a 
tooth, the tooth may be extracted with but little pain, be- 
cause the nerves are blunted in feeling. If from some cause 
there is pain in the stomach, by swallowing alcohol the pain 
ceases. The "pain is cured" because the nerves become 
less sensitive, so that we do not feel the pain. Persons who 
are under the influence of alcohol are quite insensible to 
blows, bruises, and burns, because their nerves are partially 
paralyzed. As alcohol lessens the power to feel, so does it 
weaken the power to move. A person under its influence 



ALCOHOL. 



159 



can not control his motions so well, and he is not so strong 
as when free from its influence. 

181. Stimulants. — When alcohol is taken into the system 
its first effects are to arouse and alarm the system. For a 
brief season, the person feels stronger, the heart beats more 
rapidly, and the skin is flushed. The mind of the person 
is also brightened and cheered. This is called stimulation. 
Such effects are only temporary. Similar effects are pro- 
duced by many other substances. Almost all poisons are 
stimulants. 

182. Narcotics are substances that tend to cause pa- 
ralysis of the nerves. They tend to produce depression, 
stupor, and death. Almost all narcotics produce stimulation 
at first. This is followed by depression. 

183. Alcohol as a Stimulant. — There is little doubt 
that alcohol, when taken into the system, does for a brief time 
give tone and vigor. It acts as a stimulant. The person 
feels stronger, both in muscle and mind. Its use as a stim- 
ulant is wholly needless with persons in good health. With 
persons who are invalids, the propriety of its use is question- 
able, because of the reaction that must follow stimulation, 
and the inflammation to the nerves and blood-vessels that 
must ensue. Surely no one but a skillful and conscientious 
physician is competent to administer it in any case. The 
action of alcohol is deceptive. "Whosoever is deceived 
thereby is not wise." 

184. Alcohol as a Narcotic. — The use of alcohol in 
large quantities, or in small quantities that are often repeated, 
invariably causes narcotic depression. It tends to produce 
mental and physical stupor, low temperature, and death. 
The use of alcohol, in which the narcotic effects are in the 
least degree noticeable, is, without question, evil. There is 
no difference of opinion among physiologists on this point. 

185. Stages of the Action of Alcohol. — As before 
stated, the first effect of alcohol is to produce stimulation. 



160 PHYSIOLOGY. 

This effect is temporary. The second stage of action is 
depression. In this stage, there is chilliness and fall of tem- 
perature, and loss of mental and muscular control. With 
strong persons, this stage may not be very noticeable; with 
weak persons, it is often decided and alarming. The third 
degree of alcoholic action, which is caused by a greater 
quantity of alcohol, is intoxication. In this stage, the organs 
become filled with blood, and the nervous system becomes 
greatly deranged; the mind loses its power to control the 
body; the breathing is slower; the heart beats less rapidly; 
and the temperature becomes lower. The fourth stage is 
that of unconsciousness. The individual loses all mental 
control. He can not see, hear, or feel. He lies helpless. 
The action of the heart is irregular and weak. His breath- 
ing is slow and clogged. The person borders upon death 
from the narcotic effects of alcohol. 

186. The Mind and the Nervous System. —The 
mind and the nervous system are very closely connected. 
In general, it is true that mental action is most clear and 
forcible only when the nervous system is most healthy and 
vigorous. If the nervous system is diseased or inflamed, 
the powers to understand and to control are weakened and 
unreliable. 

187. Effects of Alcohol on the Mind. — The stim- 
ulating effects of alcohol upon the nervous system usually 
cause the individual to feel bright and jovial. He fancies 
himself strong and agreeable. With some persons, however, 
the effects are to render them extremely silly. Others grow 
stupid. Still others become furious. The narcotic effects 
of alcohol cause decided mental depression and loss of 
control. 

188. Alcohol Affects the Whole Mind. — Whatever 
may be the relation of the nervous system and the mind, 
the effects of alcohol on the former cause the latter to be 
changed in all of its faculties. The effects of its action are 



ALCOHOL. 1 ( il 

seen in: (i) A confused and faulty perception of feeling — 
the person can not think rightly; (2) the memory becomes 
less clear; (3) the imagination runs wild; (4) the finer 
sensibilities are blunted; (5) there is less power of self- 
control. 

Under the influence of alcohol, the whole nature may 
be changed. The kind and gentle sometimes become cruel 
and destructive; the refined and delicate grow coarse and 
vulgar. 

The effects of alcohol on the mind, as briefly stated above, 
are caused by its paralyzing and inflaming action upon the 
brain and other parts of the nervous system. 

189. The Will Especially Affected.— The most de- 
cided and alarming effects of alcohol on body and mind is 
its tendency to weaken the will, and to fix upon the system 
a powerful appetite for alcohol. 

Because alcohol weakens the understanding and blunts 
the feelings, the person under its influence loses that keen 
sense of right and duty that is so necessary in the action of 
the will. At the same time, it is true that the nervous 
system inclines to adapt itself to the kind of treatment we 
give it. If we take alcohol, or any other narcotic, frequently 
and regularly, the system soon becomes so accustomed to 
the effects of the narcotic that it will demand the substance 
at our hands by an appetite that is very difficult to control. 
Both the mind and body are disposed to form habits. As we 
have done once under certain circumstances, we are disposed 
to do again under the same conditions. The oftener we act 
in a certain way, the more powerful becomes the habit to 
continue such action. The use of alcohol grows in this way 
to be a powerful habit, which often overcomes the strongest 
wills and most determined resolutions. The growth of this 
habit is rapid. The appetite thus formed is called the nar- 
cotic appetite. The same appetite is readily formed for 
tobacco, opium, chloral, or any other narcotic. 
Pgy.-ll. 



1 62 PHYSIOLOGY. 

190. The System Demands Increased Quantities 
of Alcohol. — Not only does the system acquire an appetite 
for alcohol if we begin the use of it, but usually it demands 
more and more in point of quantity. At first, a small quantity 
will produce a certain effect. As the system becomes accus- 
tomed to the action of the alcohol, it requires a greater 
quantity to produce the desired effect. Later in the use 
of the substance, as the system grows less sensitive, it re- 
quires still greater quantities. It is usually true that persons 
who become accustomed to the use of alcohol increase 
steadily in their habit; they drink more often, and they 
drink greater quantities. 

191. The Evil Consequences May Be Trans- 
mitted. — It is true of all living things, that the off-spring 
is like its parents. Just as every living thing originates 
from some parent body, it is equally true that the con- 
ditions of the parent affect the constitution of the off-spring. 
Children inherit from their parents both physical and mental 
features. It is equally true, that children born of parents 
who are profoundly diseased, inherit deep-seated tendencies 
to similar diseases. So, too, children whose parents are 
addicted to the use of alcohol, or other narcotics, suffer from 
the effects of such diseased conditions in their parents. 
Children whose parents are lovers of narcotics, are likely to 
inherit similar passion. Such children show these appetites 
more often than do the children from parents who are not 
given to the use of narcotics. Such children are liable to 
inherit nervous disease and weakness. 

192. Objections to the Moderate Use of Alcohol. — 
Very many persons use alcoholic drinks in what is termed 
"the moderate use" of alcohol. They use alcohol in such 
moderate quantities as not to cause intoxication. These 
persons drink moderately of wine and beer. They drink 
these substances on account of the alcohol contained in 
them. If these persons have used alcoholic beverages until 



ALCOHOL. 163 

they have formed an appetite for such drinks, the alcohol 
they take satisfies their craving, and, for this reason, they 
think it to be a very good thing. It is this tendency to 
form a narcotic appetite, that is one of the chief objections 
to the "moderate use" of alcohol. 

Alcohol is universally classed as a poison. Its moderate 
use must be objectionable, for the same reason that we 
would object to the moderate use of arsenic, strichnine, or 
other poisons. 3 

The moderate use of alcohol tends to produce diseased 
conditions of the organs of circulation; and, by inflaming 
the nervous system, it tends to weaken both body and mind. 
The example is evil. 

193. A Cause of Insanity. — Insanity is one of the most 
deplorable of human afflictions. It is now generally believed 
by physiologists that insanity is, in all cases, due to diseased 
conditions of the nervous system. Because alcohol acts in 
all cases as a brain poison, its use tends to cause conditions 
favorable to insanity. 4 

Intoxication itself is temporary insanity. It is not sur- 
prising that frequently repeated intoxication tends to produce 
confirmed mania. 

Statistics derived from various asylums, both in England 
and the United States, show that the use of alcohol is one 
among the great causes of insanity. 

A committee in England extended their observations 
through sixteen years, and reached the conclusion that as 
many as sixty out of every hundred cases of insanity in that 
country, during the time of their investigation, were caused 
by the intemperate use of alcohol. Doubtless one half the 
cases of insanity in the United States are due directly 
or indirectly to the immoderate use of alcohol and other 
narcotics. 

194. The Use of Alcohol Prepares for Crime. — The 
fact that a person who is under the influence of alcohol loses 



1 64 PHYSIOLOGY. 

the clearness of his understanding, so that he no longer 
appreciates the Tightness or wrongness of his actions, and 
does not see the consequences of his deeds, prepares him 
to do evil. 

Added to his lack of judgment, the intoxicated person 
seems indifferent to all appeals from others who would 
guide him. 

Beside the tendency of alcoholic drinks to cloud the mind, 
they inflame the passions most powerfully. For this reason, 
they put the individual in the very condition to commit 
desperate acts. Frequently, those who are kind when sober, 
are dangerous and vicious when under the influence of 
alcohol. 

The law holds the criminal responsible for his acts, al- 
though they are committed while intoxicated. Otherwise, 
all crime might prepare for its deeds, and defend itself by 
intoxication. 

Criminal judges agree in the opinion that a very large pro- 
portion of all the criminals that come before them for trial 
owe their crimes to the influence of alcoholic drinks. Police 
reports show that by far the greater number of arrests are 
for intoxication. 

195. Conclusions Concerning Alcohol. — As shown 
by the foregoing, nothing beneficial comes from the use 
of alcohol as a beverage. Its influence is evil. It tends to 
produce thirst. It disturbs the natural operations of diges- 
tion. It injures the blood. It lowers the temperature. It 
inflames the nervous system. It produces conditions that 
result in disease. It is a cause of insanity. It prepares its 
victims to commit crime. It visits its evil consequences 
from parents upon their children. It endangers the morals, 
the honor, and the happiness of itr victims. It is not de- 
signed for food or drink. Its use, even as a medicine, 
should be confined strictly to the direction of a skillful 
physician. 



ALCOHOL. ^5 



Notes. 

i. Dr. Wm. B. Carpenter, formerly Examiner in Physiology 'and 
Comparative Anatomy in the University of London, says: "The use 
of alcohol in combination with water and with organic and saline 
compounds, in the various forms of fermented liquors, deserves par- 
ticular notice, on account of the numerous fallacies which are in 
vogue respecting it. In the first place, it may be safely affirmed that 
alcohol can not answer any one of those important purposes for which 
the use of water is required in the system ; and that, on the other 
hand, it tends to antagonize many of those purposes. * * * * 
Secondly, the taking of alcoholic liquors into the stomach can not 
supply any thing which is essential to the nutrition of the system; 
since we find, not only individuals, but whole nations, maintaining 
the highest vigor and activity, both of body and of mind, without 
ever employing them as an article of diet. Thirdly, there is no 
reason to believe that alcohol, in any of its forms, can aid directly in 
the nutrition of the tissues, for it may be certainly affirmed that it is 
incapable of transformation into albuminous compounds ; and there 
is no sufficient evidence that even fatty matter can be generated in 
the body at its expense. It is quite true that some persons who con- 
sume large quantities of fermented liquors become very fat ; but the 
material for this fat is probably derived in part from the waste matter 
of the tissues. * * * Fourthly, the alimentary value of 

alcohol consists merely in its power of contributing to the production 
of heat ; but, for this purpose, it would be pronounced, on chemical 
grounds, to be inferior to fat ; and the results of the experience of 
Arctic voyagers and travelers is most decided in regard to the com- 
parative low value of alcohol as a heat-producing material. Fifthly, 
the operation of alcohol upon the living body is essentially that of a 
stimulant ; * * * being followed by a corresponding depression 
of power, in proportion as the previous excitement has been greater. 
Nothing, therefore, is, in the end, gained by its use. Its use is only 
justifiable where some temporary emergencies can only be met 
by a temporary increase of power, even at the expense of an in- 
creased amount of subsequent depression ; or where it affords aid in 
the introduction of aliment into the system, which nothing else can 
so well supply. These exceptional cases, however, will be less 
numerous, in proportion as due attention is paid to those other means 
of promoting health, which are more in accordance with nature." 



1 66 PHYSIOLOGY. 

2. Dr. Hayes, the Arctic Explorer, says: "While fresh animal 
food, especially fat, is absolutely essential to the inhabitants and 
travelers in Arctic countries, alcohol is not only completely useless, 
but positively injurious. I have known the most unpleasant conse- 
quences to result from the injudicious use of whisky for the purpose 
of temporary stimulation, and have also known strong, able-bodied 
men to become utterly incapable of resisting cold in consequence 
of the long-continued use of alcoholics." 

Dr. Frank H. Hamilton, in writing concerning an experiment, in 
the army of the Potomac, of giving to each soldier one gill of whisky 
per day, because of the great hardship and exposure to which the 
army was at one time exposed, says: " It is earnestly desired that no 
such experiment will ever be repeated in the armies of the United 
States. In our own mind, the conviction is established, by the expe- 
rience and observation of a life, that the regular routine employment 
of alcoholic stimulants by man in health is never, under any circum- 
stances, useful. We make no exceptions in favor of cold or heat or 
rain." 

3. Dr. Win. Jay Voumans says: "It is to the nervous system, and 
especially to its great center, the brain, that alcohol is first attracted 
after it has entered the circulation. It is to all intents and purposes 
a cerebral poison." 

Dr. Muzzey, of Ohio, says: "That alcohol is a poison to our 
organization, is evident from observation. * * * * What is a 
poison? It is any substance, in whatever form it may be, which, 
when applied to a living surface, disconcerts life's healthy movement. 
•:;:- * •:•:- * Such a poison is alcohol ; such, in all its forms, mix it as 
you may. It is never digested and converted into nourishment." 

Dr. James Edmunds, of England, says: " We have a great horror 
of arsenic and fifty other poisons ; while the fact is, that all these 
things are a mere bagatelle in relation to the most direct, absolute, 
immediate, and certain poisonings which are caused by alcohol." 

4. Dr. Yellowlees, Medical Superintendent of the Glamorgan 
County Asylum, England, says: "With the single exception of 
hereditary predisposition, intemperance is, by far, the most fruitful 
of all the causes of brain disease, and even hereditary predisposition 
is often but another name for parental intemperance. * * * * It 
is surely within the truth to say that half the existing cases of in- 
sanity are due directly or indirectly to this social curse. * * * No 
vice is more hereditary than intemperance." 



ALCOHOL. ^7 



Suggestive Questions. 

From what materials is alcohol made? What is fermentation? 
What two substances are produced by fermentation? What is cider? 
What change occurs in sweet cider if it is kept warm, and open to 
the air? What is distillation? What are the properties of alcohol? 
What are its uses? What is the chief use of alcohol? What gives 
the intoxicating property to wine, beer, and whisky ? How does 
alcohol differ from a natural drink ? Why does strong alcohol blister 
the mucous membrane? Does alcohol aid or hinder digestion? 
How does alcohol differ from food ? Does alcohol cause the tem- 
perature of the body to rise or to fall ? Does alcohol enable men 
to stand great exposure? Does alcohol give great strength? How 
does alcohol affect the blood ? What is true of the healthfulness 
of those who use alcoholic beverages? What organs are specially 
liable to disease by the use of alcohol ? Who are most likely to 
suffer from disease in epidemics ? What are the effects of alcohol on 
the nerves? How does alcohol allay pain? Does it make the person 
who drinks it strong or weak ? What are stimulants ? What are 
narcotics? Is alcohol needed by the healthy person? How is the 
action of alcohol deceptive? 

How does alcohol affect the mind ? What faculty of the mind 
does alcohol specially affect ? What is the narcotic appetite ? What 
substances will produce narcotic appetite ? Why do persons who 
use alcohol usually increase the quantity ? What dangers of trans- 
mission attend the use of alcohol? What are the objections to the 
moderate use of alcohol? Why does alcohol tend to cause insanity? 
How does alcohol prepare persons to commit crime ? What is the 
opinion of criminal judges concerning the effects of alcohol? What 
are the general conclusions concerning alcohol? 



GLOSSARY 



(169) 



GLOSSARY 



Ab-do'men (L. abdcrc, to conceal). The cavity containing the 
stomach, intestines, liver, etc. 

Ad'i-pose. Fatty. 

Al-bil'men (L. a/bus, white). An animal substance, much like 
the white of egg. 

Al-i-ment/a-ry (L.). Pertaining to food. 

A-nat/o-my (G. ana, through; tome, a cutting). A description of 
the structure of any living thing. 

A-or'ta (G. to hold air). The great artery that conducts the 
blood from the left ventricle of the heart. 

A'que-ous (L.), like water. 

Ar'ter-y (G. to hold air). The tubes that conduct the blood from 
the heart. 

Au'di-to-ry (L. audio, to hear). Pertaining to the special sense, 
hearing. 

Au'ri-cle (L. auris, ear). The upper cavities of the heart, having 
the shape of ears. 

Bleeps (L. bis, twice; caput, head). Having two heads. 

Bi-cus'pid (L. bis, twice; cuspis, point). Having two points. 

Bron'chi-al (G. bronkos, windpipe). Pertaining to the branches 
of the trachea for the passage of the air in the lungs. 

Bron-ehl'tis (G. bronkos, and itis, inflammation). Inflammation 
of the bronchial tubes. 

Buc-Qi-na'tor (L. buccinum, a trumpet). The muscles of the 
cheek used in blowing a trumpet. 

(171) 



172 



PHYSIOLOGY. 



Caf-fe'ine. (F.) The active principle of coffee. 

Cal-ca're-ous (L. calx, lime). Having the nature of lime. 

Cap'il-la-ry (L. capillns, a hair). Resembling a hair or other 
minute tube. 

Cap'sule (L. capsula, a small chest). A membraneous sac, or 
small bag enclosing a part. 

Car'di-ac (G. cardia, the heart). Pertaining to the heart. 

Car'pus (G.). The wrist. 

Car'ti-lage (L. cartilage). An elastic material, of a solid but 
flexible nature. 

Ca'se-me (L. caseus, cheese). The curd of milk. 

Cell. A tiny sack-like body, containing the growing matter of 
the body. 

Cer-e-belTum ( L.). The little brain. 

Cer'e-bro-spi'nal. Pertaining to the brain and spinal cord. 

Cer'e-brum (L.). The large portion of the brain filling the 
front and upper portions of the cranium. 

Cho'roid (G. chorion, a cover).. The middle cover of the ball 
of the eye. 

Chyle (G. chulos, juice). The milk-like juice derived from the 
digestion of the food in the intestines. 

Cil'i-a ( L. cilia, eye-lashes). Minute, hair-like cells that line the 
inner air passages and other parts. 

Clav'i-cle ( L. claz'is, a key). The collar bone. 

Co-ag-u-la'tion (L.) The act of turning from a fluid to a clotty 
or curdy mass. 

Co-a-lesge'. To unite. 

Coc'gyx (G.). A mass of small bones appended to the lower 
portion of the sacrum. 

CochTe-a (L. cochlea, a screw). A portron of the inner ear 
having the shape of a snail-shell. 

Con'cha (G. konchc, a shell). The outer portion of the ex- 
ternal ear. 

Con-junc'ti-va (L. con, and jungo, to join together). The thin 
membrane which lines the eye-lids and covers the front portion 
of the eye-ball. 

Con-strict'or. That which draws together. 

Con-vo-lu'tion (L. con, and volvei'e, to roll). The act of folding 
or rolling together. 

Coi/ne-a (L. cornu, a horn). The horn-like membrane forming 
the outer wall of the front portion of the eye-ball. 



GLOSSARY. 



173 



Cor'po-ra (L. corpus, a body). A name applied to various bodies 
found in the brain and in other parts of the body. 

Cor'pus-gles (L. diminutive of corpus). Tiny bodies that float 
in the plasma of the blood. 

Cor'ru-ga-tor (F.). A muscle that wrinkles the brow. 

Crystal-line (L. crvstallu/u, a crystal). Resembling crystal. 

Cuspid (L. cuspis, a point). Having one point. 

Cu'ti-cle (L. diminutive of cutis). The outer layer of the skin. 

Curtis (L. cutis, skin). The inner layer of the skin, or true skin. 



Del'toid (G. Delta, the letter /\ ). Having the shape of the 
Greek letter Delta. 

Den'tme (L. dens, tooth). The substance that forms the body 
of the teeth. 

Di'a-phragm (G. diaphragma, a partition). The partition that 
separates the chest and abdomen. 

Di-ar-rhe'a (G. diarrhea, to flow through). An unnatural fre- 
quency of evacuation of the intestines. 

Di-gas'tri-cus (G.). Having two swells. 

Di-geVtion (L. digestio, to separate). The act of separating 
the nutrient portions from the food taken into the alimentary 
canal. 

Du-o-de'num (L. duodeni, twelve). The first twelve finger- 
breadths in length of the small intestines. 

Dys-pep'si-a (G. dus, bad; peplo, to digest). That condition 
of the digestive organs in which they fail to perform digestion 
readily. 



E-mul'si-fy (L. emuVgeo, to milk). To turn into the form of 
milk. 

En-am'el (F. email). The flinty substance that covers the crown 
of the teeth. 

En-dos-mo'sis (G. endon, within; osmos, to push). The passage 
of fluids through membranes toward the inner part of the vessel. 

En-terTc. Pertaining to the intestines. 

Ep-i -glot/tis (G. epi, upon; glottis, the entrance to the larynx). 
The lid-like cover that fits over the larnyx at time of swallowing. 

E-soph'a-gus (G.). The tube that conducts the food to the 
stomach. 



174 



PHYSIOLOGY. 



Etb/moid (G. ethmos, a sieve). A bone at the base of the skull 
pierced by many holes. 

EG-sta'chi-an Tube. The passage connecting the middle portion 
of the ear with the air passages of the throat. 

Ex-cre'tion (L. excerno, to separate). The process of separating 
and casting out waste matter. 

Fe / mur(L. ). The thigh-bone. 

Fi'ber (L. fibra). A tiny filament or thread which enters into 
the structure of any tissue. 

Fi'brine (L. fibra). A substance contained in the blood, which 
coagulates into a fibrous mass. 

Fib'u-la (L. a clasp). The outer bone of the leg. 

Flexion (L. fiectio, to turn). The act of bending. 

Flex'or. A muscle that bends a joint. 

Front'al. Pertaining to the fore-part. 

Function (L. fungor, to perform). The service performed by 
any organ. 

Gan'gli-on (G. a knot). An englargement in the course of a 
nerve, or mass of gray nervous matter. 

Gas-troc-ne'mi-us (G. gastcr, the stomach; kneme, leg). The 
name of the large muscles of the leg. 

Germ. A separate portion of organic matter possessing the 
properties of growth. 

Gland. An organ designed to separate certain fluids from the 
blood. 

Glu / tee-us (G.). The name of the muscles of the hip. 

Hem/or-rhage (G. haima, blood; regmw, to burst). Bleeding. 

He-pat/ic. Pertaining to the liver. 

Hu'me-rus (L.). The bone of the arm. 

Hu'mor (L. liquid). The humors are the liquid contents of the 
eye-ball. 

Hy'gi-ene (G. huygieia, health). The science of health. 

Hy'oid. Having the shape of the letter V. The bone at the 
base of the tongue is called the hyoid bone for this reason. 

I-li'a-cus (L.). Pertaining to the groin. 
In-ci'sor (L. incido, to cut). A term applied to the front teeth. 



GLOSSARY . 



175 



In-nom-i-na'ta (L. in, not ; novicn, name). Parts having no proper 
name. 

In-ter-cos'tal (L. inter, between; costa, rib). Between the ribs. 

In-tSs'tines (L. inins, within). The canal leading from the 
stomach. 

I'ris (L. the rain-bow). The colored membrane surrounding the 
pupil of the eye. 



Lach'ry-mal (L. lachryma, a tear). Pertaining to the tears. 

Lac'te-al (L. lac, milk). A tube conveying the chyle from the 
intestines to the veins. 

LaVynx (G. larunx). The cartilaginous box containing the 
vocal cords. 

La-tis / si-mus (L.). Broadest. 

Le-va'tor (L. levo, to raise). Applied to muscles that raise 
parts. 

Lig'a-ments (L. ligo, to bind). The fibrous membranes that 
bind the joints together. 

Lum'bar (L. lumbas, loin). Pertaining to the loin. 

Lym-phat/ic (L. lympha, water). Applied to the parts that con- 
vey the lymph or watery part of the blood. 



MaTar (L. the cheek). The cheek-bone. 

Mas'se-ter (G.). The name applied to the muscles that move 
the muscles in chewing. 

MaVtoid (F.). Resembling a breast. 

Max-il'la (L.). The jaw-bone. 

Me-dulTa (L.). Marrow. 

Me-dulTa Ob-lon-ga'ta. The marrow of the spinal column con- 
tinued into the skull to join with the brain. 

Mem'brane. A thin network of fibers forming a cover or body. 

MeVen-ter-y (G. mesos, middle; enleron, intestines). The mem- 
brane by which the intestines are held to the spinal column. 

Met-a-car'pals (G. vieta, beyond; karpos, wrist). The body of 
the hand. 

Met-a-tar'sus (G. mcta, beyond; larsos, a broad flat surface). The 
body of the foot. 

Mi'tral (L. mitra, a mitre). Applied to the valves in the left 
side of the heart. 



176 PHYSIOLOGY. 

Molar (L. mo/a, a mill). The teeth used in grinding the food. 
Mo'tor (IS. motum, to move). Causing motion. 



Nar-cotTc (G. to benumb). Allaying pain, benumbing feeling, 
producing sleep. 

Na/sal (L. nasus, the nose). Pertaining to the nose. 



Oc'ci-put (L. ob, and; caput, the head). The back part of the 
head. 

Ol-fac'to-ry (L. oleo, to smell; and facto, to make). Pertaining 
to smelling. 

O'pi-iim. Dried juice of the poppy. A narcotic. 

Op / tic (G. op to, to see). Pertaining to seeing. 

Or-bic'u-lar (L. orbis, an orb). Circular. 

Or'gan. A portion of any living thing designed to perform some 
particular work in the life of the body. 

Or'gan-Ism. A living thing. 

Os-mo'sis (G. osmos, to push). The passage of fluids through 
membranes. 

Os / se-oiis (L. os, bone). Bony. 

Os'si-cle (L. diminutive of os, bone). A tiny bone. 



Pal'ate (L-). The roof of the mouth. 

Pal'pe-bral (L.). Pertaining to the eye-brow. 

Pan'cre-as (G. pan, all ; kreas, flesh). A digestive organ ad- 
jacent to the stomach. 

Pa-pil'la (L.). A minute prominence designed for the termina- 
tion of a nerve. 

Pa-ral'y-sis. Loss of nervous function, whether of intellect, 
feeling, or motion. 

Pa-ri'e-tal (L. paries, a wall). Pertaining to the walls of a cavity. 

Pa-tel'la (L. diminutive of patina, a pan). The small bone 
fitting into the knee in front. 

Pec-tor-aTis (L.). Pertaining to the chest. 

PSl'vis (L.). The basin of bones upon which the trunk is 
supported. 

Pep'sin (G. pepto, to digest). The element of the gastric juice 
which ferments the contents of the stomach. 



GLOSSARY. 



177 



Per-i-car'di-um (G. pert, around ; kardia, heart). The sack that 
encloses the heart. 

Per-i-os'te-um (G. peri, around; os, bone). The membrane 
that covers the bones. 

Per-o-ne'us. The muscle near the small bone of the leg. 

Petrous (L. petra, rock).- Rock-like. 

Pha'lanx (G. phalanx, an army). Any bone of the fingers or 
thumbs. 

Pharynx (G.). The upper portion of the esophagus. 

Phys-i-61'o-gy (G. phusis, nature; logos, discourse). The science 
of the use of organs. 

Pigment (L.)> Coloring matter. 

PlaVma (G. formed). The blood, exclusive of the corpuscles. 

Pleura (G.). A thin membrane, lining the chest and covering 
the lungs. 

Pleu'ri-sy. Inflammation of the the pleura. 

Pneu-mo'ni-a (G. pneumon, the lungs). Inflammation of the 
air cells of the lungs. 

Port'al (L. porta, agate). Pertaining to the entrance. 

Proc/ess-es. Prominences upon the bones ; also, a procedure. 

Pro-na'tor (L. pronus, face downward). Applied to muscles 
that turn the hand with the palm downward. 

Pro'to-plasm (G. protos, first; plasma, formed). The growing 
part of organisms. 

Pso'as (G. ). A muscle of the loin. 

Pty'a-lme (G. ptualon, saliva). The peculiar element of the 
saliva. 

Pul'mo-na-ry (L. pulnio, the lungs). Pertaining to the lungs. 

Pu'pil (L.). The central opening in the iris. 

Py-lo'rus (G. puloros, a gate-keeper). The opening from the 
stomach into the intestines. 

PyVi-form. Having the shape of a pyramid. 



Ra'di-us (L. a ray). The revolving bone of the fore-arm. 

Rec'tus (L.). Straight, erect. 

Re'-flex (L. re, back ; Jlectere, to turn). Being turned back. 

Re'nal. Pertaining to the kidneys. 

R§t/i-na (L. rete, a net). The inner coat of the back portion 

of the eye. 

Pgy.-12. 



178 PHYSIOLOGY. 

Sacrum (L. sacred). The bone forming the back portion of the 
pelvis. 

Sa-H'va (L-)- The fluid secreted into the mouth for moisten- 
ing the food. 

Sar-to'ri-us (L. sartor, a tailor). A muscle of the thigh. 

Scap'u-la (L.). The shoulder-blade. 

Scle-rot/ic (G. skleros, hard). The outer coat of the eye. 

Scrof'u-la. Disease of the lymphatic organs. 

Se-ba'ceous (L. sebum, tallow). Pertaining to fat. 

Se-crete'. To produce from the blood a substance different from 
the blood itself. 

Sem-i-lG'nar (L. semi, half; /una, moon). The name applied to 
valves having the shape of a half-moon. 

Sen'so-ry. Pertaining to feeling. 

Ser-ra'tus (L. scrra, a saw). Notched. 

Se'rum (L.). The water y P art °f the blood. 

Sphe'noid (G. sphen, a wedge). A name applied to a bone at 
the base of the skull. 

Spine. A thorn. The back-bone. 

Sta'pes (L. a stirrup). One of the ossicles of the ear. 

Ster-no-mas'toid. Pertaining to the sternum and the mastoid 
process. 

Ster'num. The breast-bone. 

Stim/Q-lus. That which excites. 

Sub-lingual (L. sub, under; lingua, tongue). Under the 
tongue. 

Sub-max'il-la-ry (L. sub, under; maxilla, jaw-bone). Under the 
jaw-bone. 

Su-per-cil'i-i (L. super, above; cilium, eye-lid). A muscle that 
moves the eye-lid. 

Su-pi-na/tor. A name applied to a muscle that turns the hand 
with palm upwards. 

Sut/ure (L. sua, to sew. The ragged union of the bones of the 
skull. 

Syn-o'vi-a (G. sun, with; 0011, egg-like). The fluid secreted in 
the joints. 



Tactile. Pertaining to touch. 

Tarsal (L.). The back portion of the foot. 

Tem'po-ral. Pertaining to the temples. 



GLOSSARY. I79 

Ten/don (G. fchio, to stretch). The fibrous ends of the muscles 
that join the muscles to the bones. 

Ter'es (L.). Round. 

Thal'a-mus. A rounded surface in the brain. 

The'ine. The active principle of tea. 

Tho'rax (G.). The cavity of the chest. 

Tib'i-a (L. a flute). The shin-bone. 

Tis'sue. An organization of cells. 

T6n / sils. Two glandular bodies in the throat. 

Tra'che-a (G. trachus, rough). The wind-pipe. 

Triceps (L. tres, three;, caput, head). Muscles having three 
heads. 

Tri-cus'pid (L. Ires, three; cuspis, point). Having three points. 

Tym'pa-niim (L.). The middle ear. 

Typhoid (G.). Like typhus. Applied to low fevers affecting 
the intestines. 



Ul / na (L. ulna, the elbow). The larger bone of the fore-arm. 

Vas'tus (L.). Great. 

Ven'tri-cle (L. diminutive of venter). A small cavity. 

Ver'te-bra (L. vertere, to turn). A joint or segment of the spinal 
column. 

Vil'll (L.). Minute fibers. 

Vis'ge-ra (L.). The contents of the great cavities of the body. 

Vit're-ous (L. vitrwn, glass). Like glass. 

Vol'un-ta-ry. Controlled by the will. 

Vo'mer (L. a plowshare). The bone that forms the partition 
of the nose. 



INDEX. 



(181) 



INDEX. 



Absorption, by the intestines, 
59 ; by the lymphatics, 77 ; by the 
skin, 37; by the stomach, 57. 

Accident, what to do in case 

of, 145- 

Air, changes in, 84; composi- 
tion of, 80 ; demand for, 79 ; 
effect on skin, 41 ; its function in 
the blood, 85. 

Air cells, 82. 

Air passages, 81. 

Albumen, 48. 

Albuminoids, 47- 

Alcohol, 153; a poison, 112, 
163; as drink, 49, 52, 155; as 
food, 49, 52, 156; as heat-pro- 
ducer, 49, 52, 156; as narcotic, 
159; as stimulant, 159; cause of 
insanity, 163 ; conclusions con 
cerning, 164; craving for, 50, 112 
dangers of, 49 ; effects on blood, j 
49, 157 ; effects on mind, 50, 112, 
160 ; effects on mucous membrane, 
155 ; effects on muscles, 49 ; effects 
on nerves, 49, 158; effects on 



nerve centers, ill; effects on 
nerve fibers, ill; effects on ner- 
vous system, in ; effects on stom- 
ach, 156; effects on vital organs, 
49, 158; effects on will, 161 ; from 
what made, 153; increased de- 
mand for, 162; objections to mod- 
erate use, 162 ; prepares for crime, 
163; properties of, 154; stages of 
action, 159; uses of, 154. 

Alcoholic drinks, classification 
of, 52. 

Alimentary canal, 54. 

Animals, 8, 10. 

Aorta, 69. 

Aqueous humor, 125. 

Arbor vita?, 102. 

Arteries, 69, 70, 75. 

Articulation of sounds, 90. 

Assimilation, 72. 

Auricles, 68. 

Ball and socket joints', 18. 
Bathing, 38. 

Beating of the heart, 69. 
( 183 ) 



1 84 



PHYSIOLOGY. 



Beans, 51. 

Beef, 51. 

Beer, 49. 

Biceps muscle, 26. 

Bile, 59, 63. 

Bites, what to do for, 147. 

Blind, how they read, 119. 

Blood, 66 ; changes by respira- 
tion, 84; composition of, 75; cor- 
puscles, 66, 76 ; plasma, 66. 

Bodies, kinds of, 7, 8 ; parts 
of, 9. 

Bones, 12, 22; broken, 20, 23, 
145 ; color plate, opposite title 
page; composition of, 16; growth 
of, 20 ; hygiene of, 21; number 
of, 12; of the chest, 14; of the 
ear, 131, 133; of the extremities, 
15; of the face, 13 ; of the head, 
13 ; of the trunk, 13 ; of the skull, 
13, 22 ; outline of, 24 ; section of, 
18; structure of, 17, 18. 

Brain, 100 ; convolutions of, 
102 ; divisions of, 106 ; exercise 
of, no; hemispheres of, 102, 105; 
injuries to, HO; membranes of, 
101 ; rest of, Hi; sensibility of, 
1 14 ; weight of, 105. 

Breathing, 138. 

Broken bones, 20, 145. 

Bronchial tubes, 82. 

Burning house how to escape 
from, 147. 

Burns, treatment of, 39, 146. 

Butter, 51. 

Capacity of lungs, 84. 
Capillaries, 7°- 
Care of the sick, 142. 
Carpal bones, 16. 
Cartilage, 22. 



Caseine, 48. 

Caustics, 155. 

Cells, 10. 

Centers, nervous, 99. 

Cerebellum, 102. 

Cerebro-spinal system, 100. 

Cerebrum, 102. 

Changes in air by respiration, 
84 ; in blood by respiration, 84 ; 
in blood by circulation, 65. 

Cheese, 5 1 - 

Chest, 15 ; movements of, 8^. 

Chill, 74. 

Chloral hydrate, 114. 

Chloroform, 114. 

Choking, 147. 

Choroid coat, 125. 

Chyle, 59. 

Cider, 49. 

Cilia, 82. 

Circulation, color plate show- 
ing system of, opposite page 65 ; 
general plan of, 65 ; hygiene of, 
74 ; organs of, 67 ; outline of, 78 ; 
portal, 76 ; pulmonary, 72 ; sys- 
temic, 72 ; traced, 71. 

Classification of alcoholic 
drinks, 52. 

Clavicle, 15. 

Cleanliness, 137 ; of the cloth- 
ing, 38, 137; of the colon, 63. 

Clothing, cleanliness of, 38, 
137 ; kinds of, 40 ; uses of, 40. 

Coagulation, 67, 76. 

Coats of alimentary canal, 54; 
of eye, 124; of intestines, 58. 

Coffee, 49> 5 2 > "3- 

Colds, how taken, 41, 74; how 
treated, 41. 

Colon, 57, 63. 

Consumption, 91. 



INDEX. 



185 



Cooking, 5°- 

Corn meal, 51. 

Cornea, 125. 

Corns, 40. 

Corpuscles of blood, 66, 76. 

Cosmetics, 40. 

Crime, alcohol prepares for, 
163. 

Crystalline humor, 125. 

Cultivation of the senses, 119; 
of the voice, 90. 

Curvature of spine, 22. 

Cuticle, 34; renewal of, 39. 

Cutis, 34, 36. 

Deafness, 133. 

Diaphragm, 83, 

Diarrhea, treatment of, 147. 

Diet, mixed, 48, 51 ; plain, 51. 

Digestion, 54; hygiene of, 60 ; 
intestinal, 57 ; observed, 63 ; out- 
line of, 64 ; stomach, 56. 

Digestibility of food, 63. 

Dislocation of joints, 20. 

Distillation, 154. 

Drink, true, 49, 136, 155. 

Drinks, alcoholic, 49, 155. 

Drowning, 146. 

Duodenum, 59. 

Ear, 130; bones of, 131; hy- 
giene of, 132; inner ear, 131, 133; 
parts of, 130; section of, 131. 

Eating between meals, 61; 
manner of, 60, 61, 135; regularity 
of, 61 ; what to eat, 135. 

Eggs, 51. 

Element of nervous system, 99. 

Enamel, 43 ; how injured, 45. 

Epiglottis, 88. 

Esophagus, 54, 56. 



Eustachian tube, 131. 

Excretion, 94 ; organs of, 94 ; 
how performed, 95; hygiene of, 
96 ; outline of, 97. 

Exercise, 29; effects of, 41, 74, 
96, no. 

Expiration, 84. 

Extremity, lower, 16 ; upper, 
16. 

Eye, 123 ; ball, 124; coats of, 
124; diagram of, 126; dissection 
of, 128; humors of, 125; hygiene 
of, 127; image of, 126; muscles 
of, 124; protecting parts of, 123; 
section of, 125. 

Fainting, 75. 
Far-sightedness, 127. 
Fasting, 77« 
Fats, 48. 

Femur, section of, 17. 
Fermentation, 153; of cider, 
153 ; of grains, 154; of molasses, 

!54. 

Fiber, motor, 104 ; muscular, 
27; nerve, 99, 104; sensory, 104. 

Fibrine, 48, 66; of the blood, 
66, 67. 

Fibula, 16. 

Filters, 53. 

Finger, nerves of, 118; section 
of end, 35. 

Flesh food, 51. 

Food, amount required, 61; 
composition of, 51; definition of, 
47; digestibility of, 63; kinds of, 

47- 

Foods, sources of, 47 ; uses of, 

47- 

Foreign substances as food, 
62. 



i86 



PHYSIOLOGY. 



Gall bladder, 56. 

Gastric fluid or juice, 57. 

Gastric glands, 57- 

Glands, 62; lachrymal, 124; 
of the intestines, 58; of the skin, 
36; of the stomach, 57; perspir- 
atory, 37 ; sebaceous, 36. 

Habit, 109, 141. 
Hair, 35, 36, 40. 
Hand, 31 ; organ of touch, 117; 
uses of, 118. 
Headache, 77. 
Health, general suggestions, 

143. 

Hearing, 130; manner of, 132; 
organ of, 130. 

Heart, 67 ; action of, 68; beat- 
ing of, 69, 76; passages of, 68; 
sounds of, 76; valves of, 68. 

Heat, how produced, 85. 

Heredity of disease, no, 112. 

Hinge joints, 18. 

Human body, 8. 

Humerus, 15. 

Humors of the eye, 125. 

Hygiene of bones, 21; of cir- 
culation, 74; of digestion, 60; 
of ear, 132; of eye, 127; of excre- 
tion, 96; of food, 50; of nervous 
system, 110; of respiration, 85; 
of skin, 37 ; of teeth, 44. 

Hyoid bone, 13. 

Image, 126. 

Impurities, how formed, 85, 
94; how removed, 95. 

Insanity, no, in, 112; alco- 
hol a cause of, 163. 

Inspiration, 83. 

Intercostal muscles, 83. 



Intestines, 54, 56, 57, 58; ab- 
sorption, 59; digestion, 57; glands, 
58; juices, 58. 

Intoxicating beverages, 155. 

Intoxication, 160, 163. 

Involuntary muscles, 29. 

Iris, 125. 

Joints, 18, 23; injury to, 19. 
Kidneys, 95. 

Lachrymal ducts, 124; glands, 
124. 

Lacteals, 59, 60; section of 
ends, 61. 

Larynx, 88. 

Ligaments, 19. 

Light, 126. 

Liver, 56, 63 ; circulation 
through, 76.- 

Lungs, 81, 82; diseases of, 91 ; 
volume of, 84, 90. 

Lymphatics, 73. 

Mastication, 54, 55. 

Medulla Oblongata, 103. 

Meals, 61. 

Membranes, of the brain, 101; 
of the tympanum, 131. 

Mesenteries, 60. 

Metacarpal bones, 16. 

Metatarsal bones, 16. 

Milk, 51. 

Mind, 160. 

Mineral foods, 47. 

Motor fiber, 104. 

Muscles, action of, 27, 31; ar- 
rangement of, 27 ; classes of, 27, 
32; composition of, 30; contrac- 
tion of, 26; involuntary, 29; 



INDEX. 



187 



names of, 32; of the body, 26; of 
the eyes, 124; outline of, 32; re- 
laxation of, 26; structure of, 26, 
27; uses of, 31 ; voluntary, 28. 

Muscular cells, 27. 

Muscular fibers, 27. 

Muscular system, 26 ; color 
plate showing the, opposite page 
32. 

Nails, 35, 40. 

Narcotic appetite, 112, 113; 
poisons, 149. 

Narcotics, effects of, ill, 159. 

Near-sightedness, 127. 

Nerve cells, 98. 

Nerve centers, 98. 

Nerve fibers, 99, 104. 

Nerves, 98; of the finger, 118; 
of the sight, 125; of the smell, 
121; of taste, 119; of touch, 118; 
roots of, 104; spinal, 104. 

Nervous system, 98, 100; ar- 
rangement of, 105; divisions of, 
100; cerebro-spinal, 100; color 
plate of, opposite p. 112; connec- 
tion with mind, 160; element of, 
99 5 hygiene of, 109 ; outline of, 
115; sympathetic, 107. 

Nervous tissue, character of, 
98; function of, 108. 

Nitrogen, 81. 

Oat meal, 51. 

Occupation, 139. 

Opium, 113. 

Organs, definition of, 8 ; of cir- 
culation, 67; of excretion, 94; of 
respiration, 79; of sight, 123; of 
smell, 121; of taste, 119; of touch, 
117; systems of, 9 



Osmosis, 63. 

Osseous system, 12. 

Outline, Topical, of bones, 24; 
of circulation, 78; of digestion, 
64; of excretion, 97; of foods, 
53 ; of introduction, 1 1 ; of muscles, 
32; of nervous system, 115; of 
respiration, 93 ; of skin, 42 ; of 
special senses, 134; of teeth, 46. 

Oxygen, 80. 

Pain, 116. 

Pancreas, 56, 63. 

Pancreatic juice, 59. 

Papillae, 119. 

Paralysis, 109, n 1, 114. 

Patella, 16. 

Pelvis, 15. 

Pepsin, 57. 

Perfumes, 40. 

Periosteum, 18. 

Perspiration, 37. 

Phalanges, 16. 

Plants, 8, 10. 

Plasma, 66, 75. 

Pleura, 8^. 

Poisons, 148. 

Pork, 51. 

Potatoes, 51. 

Portal circulation, 76. 

Pupil, 125. 

Purifiers of water, 53. 

Pulmonary artery, 69. 

Pulmonary circulation, 72. 

Pulse, 69. 

Pylorus, 56. 

Radius, I5> 22 - 
Rectum, 58. 
Reflex action, 109. 
Rest, 29. 



1 88 



PHYSIOLOGY. 



Respiration, 79; frequency of, 
84; general plan of, 80; hygiene 
of, 85 ; organs of, 81 ; outline of, 

93- 

Retina, 125. 
Rice, 51. 
Rickets, 23. 
Ribs, 15. 

Saliva, 55- 

Salivary glands, 55. 

Scapula, the, 15. 

Sclerotic coat, 124. 

Sebaceous glands, 36. 

Secretion, 62. 

Self study, 9- 

Sensation, special, 117. 

Senses, cultivation of, 119; 
special, 117. 

Sensibility, special, 116. 

Sensitiveness, 121. 

Sensory fibers, 104. 

Serum, 66. 

Sick, the care of, 142. 

Sickness, what to do, 145. 

Sight, 123; how we see, 126; 
nerves of, 123; uses of, 123. 

Skeleton, 12; of animals, 21. 

Skin, 34; glands of, 36; hy- 
giene of, 37 ; outline of, 42 ; sec- 
tion of, 35; structure of, 34; uses 
of, 34- 

Skull, 13. 

Sleep, in, 114. 

Smell, 121. 

Sound, 132. 

Spinal column, 13; curvature 
of, 22. 

Spinal cord, 103. 

Spinal nerves, 104. 

Sprain, 20. 



Starch, 48, 62. 
Sternum, 14. 
Stimulants, III, 159. 
Stimulation, 112. 
Stomach, 54, 56 ; digestion, 56 
section of, 57. 
Suffocation, 146. 
Sugars, 48, 62. 
Sunlight, 41. 
Sunstroke, 147. 
Sutures, 13. 
Swallowing, 55, 62, 
Sympathetic system, 107. 
Synovial membrane, 19. 
Systems of organs, 9. 
Systemic circulation, 72. 

Tarsal bones, 16. 
Taste, 119. 

Tea, 49, 5 2 > "3- 

Teachers, suggestions to, 63. 

Tears, 124. 

Teeth, 43 to 46. 

Temperature, regulation of, 37. 

Tendons, 27. 

Thoracic duct, 60. 

Thirst, 47, !55- 

Tibia, 16. 

Tissues, 10; names of, 10; 
nervous, 98, 108. 

Tobacco, 113. 

Tongue, 120. 

Touch, 117; nerves of, 118; 
judgment of form and distance, 
122. 

Trachea, 82. 

Transmission of evil tenden- 
cies, 162. 

Tympanum, 130. 

Ulna, the, 15, 22. 



IXDEX. 



89 



Valves of the heart, 68. 
Vapor of water, 81. 
Vein, portion of a, 71. 
Veins, 7 1 - 
Ventilation, 85, 91. 
Ventricles, 68. 
Vertebra, 14. 
Villi, 59. 
Villus, a, 59. 
Vitreous humor, 125. 
Vocal cords, 88. 
Voice, 88, 89, 90. 



"Waste matter, removal of, 72. 

"Water, 49 ; clangers from im- 
purities, 136; how to purify, 49; 
purifiers, 53 ; rules concerning 
use of, 50. 

"Watery vapor, 81. 

Weight of brain, 105. 

Wheaten flour, 51. 

"Whiskey, 49, 52. 

"Will, affected by alcohol, 161. 

Wine, 49. 5 2 - 

Wounds, treatment of, 145. 



Eclectic Educational Series. 



SCIENCE. 



Norton's Physics. 

Elements of Physics for Academies and Common Schools. By So 
A. NORTON, A. M., Prof, in Ohio Agricultural and Mechanical College. 
i2mo, cloth, 286 pp. Illustrated. 

Norton's Natural Philosophy. 

The Elements of Natural Philosophy. By S. A. Norton, A. M. 
A new treatise, embracing latest discoveries to date of publication 
i2rno, cloth. 458 pp. and complete Index. 350 Illustrations. 
Norton's Chemistry. 

The Elements of Chemistry, by S. A. Norton, A. M. i2mo, cloth, 
300 pp. Illustrated. 

Andrews's Elementary Geology. 

An Elementary Geology, designed especially for the Interior States. 
By E. B. Andrews, LL.D., late of the Ohio Geological Corps, and Pro- 
fessor in Marietta College. i2mo, cloth, 269 pp. and Index. 432 
illustrations. 

Brown's Physiology. 

Manual of Physiology and Hygiene. By R. T. Brown, late Chemist- 
in-Chief in the Department of Agriculture, Washington, D. C. Divided 
into 50 lessons. i2mo, cloth, 288 pp. Illustrated. 

Schuyler's Logic. 

The principles of Logic. By A. Schuyler, LL.D., Preset of Bald- 
win University ; author of Algebra, Trigonometry and Surveying, etc. .. 
I2mo, cloth, 168 pp. 

Andrews's Constitution. 

Manual of the Constitution of the United States. Designed for the 
instruction of American youth in the duties, obligations, and rights of 
citizenship. By Israel Ward Andrews, D. D., President Marietta 
College. i2mo, cloth, 408 pp., with Index and Appendices, embracing 
important state papers. 

"In each aspect of its usefulness, the work can not fail to meet with approval 
and as a text-book, it is by all odds the best of its kind." — The Nation. 

Gow's Morals and Manners. 

Good Morals and Gentle Manners. A systematic text-book on 
Moral and Social Law. By Alex. M. Gow, A. M„, Suft Public 
Schools, Evansville, Ind. i2mo, 252 pp. 



Published by 

Van Antwerp, Bragg & Co., Cincinnati and New York, 



JUST PUBLISHED. 



CGIiEGlUG (©HA^PS 




>OF- 

h 

•AND 




PHYSIOLOGY. 

BY 

Dr. Andrew Wilson, F. R. S. E. 

/. The Skeleton, Muscular System, Digestive Organs, etc. 
II. The Organs of Digestion, Circulation and Excretion. 
III. The Nervous System and Organs of Sense. 

Size, 54x46. Price, $15. OO per Set. 



These beautiful charts, brilliantly colored to life, are of 
such large size that each detail is clearly shown. Drawn by 
an eminent anatomist, their accuracy can be relied on. 

The price is put so low that every school-room above the 
primary grade should contain a set. 

They are mounted on heavy canvass, the surface varnished, 
and an unusually substantial roller and stick supplied. 

These charts will be be expressed prepaid to any office in 
the United States on receipt of the price named. 

PUBLISHED BY 
VAN ANTWERP, BRAGG & CO. 

CINCINNATI, O. 



LIBRARY OF CONGRESS 




° 005 526 928 2 ^ 



